Nigel Dodds last summer helped to keep Jeremy Corbyn out of Downing Street. As Westminster Leader of the Democratic Unionist Party, he was a key figure in negotiating the confidence and supply agreement which enabled Theresa May to carry on as Prime Minister and averted a second general election.

But in this interview, Dodds issues a stern reminder that maintaining the integrity of the United Kingdom is for the DUP “an absolute red line” in the Brexit negotiations.

He warns that people are exploiting the Irish border issue “to thwart Brexit if they can”, and says the Dublin Government have “talked about almost the annexation of Northern Ireland”.

Dodds nevertheless expresses complete confidence that May will insist on the whole of the UK leaving the Customs Union and Single Market. And he believes that once Dublin realises this, it will be possible to ensure free trade across the Irish border in a way that greatly benefits both the UK and the Republic.

The interview took place in Dodds’ fine, panelled room overlooking the River Thames, which is adorned by a wonderful Beerbohm cartoon of Sir Edward Carson, and by a framed inscription recording the award last November to Dodds of Negotiator of the Year by The Spectator.

ConHome: “Under what circumstances would you not support the Conservatives? Because there is a fairly obvious problem about not supporting the Conservatives, which is that we could end up with Mr Corbyn, who from many people’s point of view, including Unionists like yourself, would be a very unwelcome prospect.”

Dodds: “That’s right. One of the reasons why we entered into the confidence and supply agreement was to keep Corbyn out of Number Ten, to avoid an early general election. And you know, so far, so good, because I think Corbyn being in Number Ten would be a disaster not just for Northern Ireland but for the UK, and actually dangerous for the UK in every sense.

“Yeah we’re very mindful of Corbyn and the people round him like John McDonnell who’ve said and done terrible things as far as Northern Ireland is concerned over the years.

“However the fact is that under the Fixed-term Parliaments Act there is a lot that the DUP can not support the Government on, and avoid a general election.

“And, you know, for us there is the fact that if as a result of the Brexit negotiations for instance there was to be any suggestion that Northern Ireland would be treated differently, in a way for instance that we were part of a customs union and a single market and the rest of the UK wasn’t – if there was anything like the EU’s definition of the backstop arrangements that was agreed in December – for us that would be a red line, which we would vote against the Government, because you might as well have a Corbyn government pursuing openly its anti-Unionist policies as have a Conservative Government doing it by a different means.

“The Government’s well aware that when it comes to Brexit and the United Kingdom, the United Kingdom has to leave the European Union and all its institutions together. So I’ve no reason, absolutely none whatsoever, to believe that the Government won’t do that. The Prime Minister’s been very, very clear.

“But that is an absolute red line for us, and if the Government were suggest that Northern Ireland were to be treated differently, in a way that Northern Ireland didn’t agree to – I mean there are areas, for instance the single electricity market, that make sense – but on the big issue of customs union, single market regulation, border down the Irish Sea, that would cross a very big red line for us.”

ConHome: “This morning my eye was caught by the leader in the Financial Times, which makes the conventional view of a large part of the London Establishment that Britain should stay in the Customs Union. Now from your point of view, provided the whole of the UK stayed in the Customs Union, would that be all right?”

Dodds: “Well, the fundamental thing for the Democratic Unionist Party is that whatever we end up with after Brexit, the United Kingdom is kept intact, economically, politically, constitutionally.

“However, we do have views as to the form of Brexit. So our view is that staying inside the Customs Union, and this is the United Kingdom staying inside the Customs Union, is not delivering on the referendum result.

“So I think we do have to leave the Customs Union and the Single Market. I agree with the Prime Minister entirely on that. Otherwise you’re left in this incredibly bizarre situation where you’re a rule-taker from Brussels, you enter into these customs arrangements with third countries where they can access your market but you can’t access their market in that scenario, when you’re not a member of the EU.

“So it’s the worst of all worlds. So we believe that the proposals put forward by the Prime Minister in the paper last August for either a customs partnership, whereby we would collect the revenues and then pay them back if the goods go to Europe, or the maximum facilitation streamlined approach, we believe in that, but we don’t believe in staying in the Customs Union.

“But at the end of the day, as long as Northern Ireland is in lockstep with the rest of the United Kingdom, for us that’s the fundamental point.”

ConHome: “And you think this will be done with free movement across the border? We’ve had free movement of people since 1923.”

Dodds: “Well free movement of people, the common travel area, has been agreed. And at the outset of these negotiations, that was the one issue that everybody kept talking about. The main concern of a lot of people, that they could be stopped at the border and checked, that’s not going to happen. All the arrangements under the common travel area are going to continue as before, which is excellent.”

ConHome: “And there are differences at the moment, of currency, VAT rates…”

Dodds: “You see, this idea there is no border in Ireland is a fallacy. There is a border. There’s no infrastructure on the border – well, I say there’s no infrastructure, I live quite near the border and I passed the other day and there was a set of cameras right on the border.

“So there is some infrastructure already. There’s a currency border, we change our money, as you say different tax rates, different regulations on all sorts of areas.

“You know the very fact that we complain a lot and there are prosecutions for fuel laundering and fuel smuggling proves the point that even within the EU there is smuggling and borders and all the rest of it, and that all has to be managed.

“The point is can we ensure we don’t add on the border itself any extra infrastructure that isn’t there already. That’s the key point. And I think recently Boris Johnson made this point, and he was criticised very heavily for almost suggesting that he was looking to reinforce the border. His point was that there is a border already, our job is not to add to it.”

ConHome: “At one point he suggested it was like going from Camden to Westminster.”

Dodds: “Yeah, well, it wasn’t the most politically astute illustration to use, it was bound to be jumped on, it’s certainly a more significant border than that. But his point was that you can actually move across without any stoppages or any infrastructure, and I think that’s true.

“So I’m pretty optimistic about the border. The people who are talking most about the border, some of them are people who have never talked at all about or been interested in Northern Ireland previously, or been interested in the border whatsoever.

“But they’re using it entirely to push their own version of Brexit, or to bind the United Kingdom into the Customs Union and the Single Market. Or in some cases they want actually to thwart Brexit if they can. They’re not interested in the Belfast Agreement, the peace process, or the border arrangements, because they’ve never shown any interest previously.

“But they think this is a good opportunity to try to shape the form of Brexit for the whole of the UK.”

ConHome: “Could you specify who these people are?”

Dodds: “There are people in the Dublin Government who are wanting to use the border as a means, not necessarily only, they would like to keep Northern Ireland separate from the United Kingdom if they could, but their real aim is to try to keep the whole of the United Kingdom inside the Customs Union and the Single Market, because that suits the Irish Republic.

“And I understand entirely why they would want to do that. But they shouldn’t be using the border issue to try to achieve that. I think there are people clearly in the Establishment here at Westminster, and in the press and media, who continually harp on about the border, and as I say they’ve never shown any interest in Northern Ireland debates.

“Of course you have the usual suspects like Tony Blair and John Major and people like that, who have gone a step further. What concerns me is their use of the peace process and saying peace is in danger as a result of Brexit, which I think is a deeply reckless thing to be saying. I mean there is no evidence at all and if they do have evidence that the IRA are going to go back to war over customs posts then they should tell us, and they should be quite explicit about who it is.

“But there is no kind of sense from anybody that we are going to go back to those dark days. And to talk like that is almost giving cover to some of those dissident groups, very small in number, who would use any excuse and who are at war in Ireland using terrorism even without Brexit. So you know I think it is highly dangerous talk and they should desist, if they’re really interested in peace and stability in Northern Ireland.”

ConHome: “When you first went into the arrangement with the Conservatives, were you angered at the level of ignorance and prejudice shown by many bien-pensant people in London towards the DUP?”

Dodds: “Not anger, just resignation towards the inevitable level of ignorance there is of Northern Ireland matters. It subsided relatively quickly when people delved a little bit deeper and looked at the Democratic Unionist Party of today, because what you were  getting were quotes from the Seventies and early Eighties. The Democratic Unionist Party is a party that had been for ten years the leading party of government in Northern Ireland, sharing power with Sinn Fein.”

ConHome: “When do you think there will be a return to devolved government? How dissatisfied are you with direct rule?”

Dodds: “Well we want devolution. What’s happening at the moment is we have neither direct rule nor devolution. It cannot last. It’s constituents of all parties who are suffering as a result of an absence of decision making. We would go back into government tomorrow. We were not the party that collapsed devolution.”

ConHome: “Dublin was so worried by the result of the EU referendum, and the effect it would have on the Republic. But do you think in the end in the end they’ll agree to some sort of reasonable settlement?”

Dodds: “Well one would like to think there will in the end be a reasonable settlement. Up to now Simon Coveney, the Department of Foreign Affairs, have talked in very, very aggressive terms. They’ve talked about almost the annexation of Northern Ireland.”

ConHome: “They can’t have used that word.”

Dodds: “Well they haven’t used that word. They’re really in this to try to get the whole of the United Kingdom inside a Customs Union and a Single Market. But failing that, their secondary aim is that Northern Ireland should remain inside the Single Market and the Customs Union, and they’ve been quite explicit about that.

“And the EU definition of the backstop arrangements which came out in March, and which the Prime Minister quite rightly rejected, would have implemented that vision – would have created a border down the Irish Sea. It is to all intents and purposes the break-up of the United Kingdom.

“So I say that the effect of what they’re saying would be the annexation of Northern Ireland. That would be utterly unacceptable. The arrangements that they talk about would not only be politically and constitutionally disastrous for the UK as a whole, but would actually cut Northern Ireland off from its main market.

“The vast bulk of our sales out of Northern Ireland goes to the United Kingdom market. This is not just politically aggressive, it is economically catastrophic for Northern Ireland.

“So the only purpose in putting this forward as a proposition by Dublin is to advance their political aims of a united Ireland. There can be no other explanation for it.

“What I think will happen in the end if the British Government are firm and resolute and say we are leaving the Customs Union and we are leaving the Single Market, we’re not going to be bullied into doing otherwise, we have to make sensible arrangements for a frictionless border not just between Northern Ireland and the Irish Republic but also between Dover and Calais, which is even more important in many ways in terms of the overall context.

“At that point the Irish are going to say, well the choice here is between a no deal scenario which is absolutely catastrophic for the Irish economy, or getting a sensible arrangement. But at the minute I think what is in the minds of both Dublin and some people in Brussels, given the machinations in the House of Lords, given maybe some of the backbench behaviour in the Tory Party, supporting overall retention of the Customs Union, that they still cling to the hope and belief that Britain can be forced to stay in the Customs Union.”

ConHome: “But once they admit they can’t get that, there is in fact a greater alignment of interests?”

Dodds: “Yes. They need to get to the point where they realise they’ve got to get down to sensible, practical arrangements. They’ve got to have a free-trade deal, that’s very much in the Irish interests. So yes, there should be an alignment of interests between the Irish Republic and the UK. It’s very much in the Irish interest to have that free-trade deal and to have as little checks and so on, customs regulation-wise, as can be.”

ConHome: “In a funny sort of way, it’s just conceivable that although the election was a dreadful shock for Theresa May and for the Conservative Party, having a weak Prime Minister putting through Brexit, rather than a Prime Minister who’s an elected dictator with a majority of 150, is actually a better way of working out a viable consensus on this subject, rather than just thinking you can just lay down the law on everything.”

Dodds: “Well I’m sure Theresa May and her advisers don’t think that [laughter].”

ConHome: “What were your feelings when you realised you were in this incredibly strong position?”

Dodds [after searching for the right words]: “It’s a great responsibility when you realise you are going to be critically involved. But one of bemusement almost, because in 2015 we had assumed that there was going to be a hung parliament and the DUP might well come into play, because the polls were neck and neck.

“Ed Miliband was wooing the DUP like mad. I remember he spent half a day in my constituency, in the heat of the general election. This puts into perspective some of the Labour criticism of our deal with the Tories, because they were quite happy to consider doing a deal with us in 2015.

“In 2017 we had to revisit our plans and proposals for 2015. We had been through all the psychological preparation for being in that position in 2015.

“And that is why when we entered into negotiations, we did so in a fairly focussed way. We weren’t bounced into anything.”

ConHome: “You and Arlene Foster didn’t look quite as delighted as Nick Clegg was in 2010. There were various photographs, but no rose garden moment.”

Dodds: “Well we’re not in a full-blown coalition with ministerial office. He seemed quite carried away with that, but he was soon brought back to earth. The arrangement that we have entered into is one that we’re entirely comfortable with.”

ConHome: “How often does the Co-ordination Committee between you and the Conservatives meet, and who goes to that?”

Dodds: “Arlene Foster and Theresa May are obviously always able to come. But myself, Jeffrey Donaldson and Sammy Wilson are there for the DUP, and then it was Damian Green but now David Lidington, the Chief Whip Julian Smith, the Treasury and the Brexit department – that’s the main, but others come as and when necessary. depending on the nature of the agenda.”

He added that there are weekly meetings at a high level. Dodds looks safe in the knowledge that the DUP cannot be ignored.