Andrew Lilico is an economist and political writer.

A recent Evening Standard leader declared: “Mr Cameron…will be campaigning for Britain to remain in the EU even if he does not get the concessions he wants” in his renegotiation. This is claimed very widely across the UK media.

It is not Cameron’s own stated position. His position, stated repeatedly by himself and his Foreign Secretary Philip Hammond, is that, as he put it at a recent Q&A: “I have always said what I want is an outcome for Britain that keeps us in a reformed EU. But I have also said we don’t know the outcome of these negotiations, which is why I have always said I rule nothing out.”

So although the Prime Minister says he intends to secure a renegotiated deal that allows him to campaign to stay in but rules nothing out if he does not secure such a deal, the common claim in the UK press is that he will campaign to stay in regardless of what he gets – i.e. they rule out any possibility of him, say, campaigning for Out or declaring himself neutral in the EU referendum.

Why the difference?

We can separate those commentators that do not believe the Prime Minister when he suggests he might support Out or remain neutral into five main camps.

First there are those that want the UK to leave the EU regardless of what sort of deal the Prime Minister gets. Their real concern is not that the Prime Minister will get something insubstantial and then campaign to stay nonetheless, but that he could get something significant, which would constitute a significant renegotiation.

That’s the last thing they want. So, pre-emptively, they want to undermine his credibility if he comes back and says he got something significant, by claiming that he’s bound to claim that because he always intended to campaign in favour of staying regardless of what he got.

Closely related to this first group is the second: those that will campaign for In regardless of what the Prime Minister gets. This group wants to establish that it doesn’t matter what happens in the renegotiation — we should be In anyway. This group seeks to claim Cameron as an ally.

A third group are a group of professional political cynics. This groups trades off telling the tale that politicians always lie and dissemble and you should never believe anything they say.

So when Cameron says he wants a serious renegotiation and rules nothing out if he doesn’t get it, this group declares that what that really means is that he’ll get nothing then roll over and campaign for In anyway. That’s all very entertaining to read, but it’s corrosive.

A fourth group appears to me to be commentators that do not understand the Conservative Party or David Cameron. This group thinks that Cameron has offered a referendum simply to try to kill off agitation within the Conservative Party to either renegotiate or leave the EU.

They seem to think that most Conservatives are at least reasonably content with the status quo except insofar as it leads to a significant rump of MPs and members going in about Europe all the time or leaving to join Ukip.

They thus believe that a cosmetic “renegotiation”, involving a few minor concessions that allowed the Party to pretend to the public that something important had changed, would see off the get-outers for at least a few years whilst uniting the rest against them.

That last view seems to me to importantly misunderstand both the Conservative Party and David Cameron.

The Conservative Party voted against ratification of the last three EU Treaties (Amsterdam, Nice and Lisbon), having been seriously split on whether to ratify the one before that (Maastricht). The Party campaigned in four general elections in a row for a significant repatriation of powers from the European Union.

If the Prime Minister comes back with something that a large majority of Conservative MPs and members believes to be a significant renegotiation and repatriation of powers, most of them will support him.

But if he comes back with something purely cosmetic, pretends it is something significant, and then makes it government policy to campaign for staying In, the splits in the Conservative Party will be catastrophic.

Some commentators seem to imagine that Cameron would be prepared to tolerate enormous splits in his party if that is the price for staying in the EU. But why?

Cameron does not care much about the EU either way. Indeed, many of his pronouncements on it (e.g. regarding renegotiation of free movement of persons — something he was still claiming he was going to renegotiate even in the leaders’ debate before the General Election) indicate he and his advisors simply do not understand what the EU is.

(They appear to regard it as some kind of means by which the countries of Europe do collective business with each other, a sort of coordination mechanism for decisions that remain fundamentally national. If that was ever what it was, that is not what it has been since about 1992.)

Cameron thinks the EU is somewhere between a bit of a distraction and an impertinent and irritating restriction upon his ability to execute his own preferred policies. He is not an emotional Europhile — a Ken Clarke or a Michael Heseltine.

I cannot imagine Cameron being willing to make any important sacrifices in order to keep in with the EU.

Suppose that, given he got only a paltry deal from his EU partners, Cameron then had to choose between creating a massive split in the Conservative Party and either declaring the government neutral or actively campaigning to leave. Do you really imagine that Europe is so important to him that he would prefer to destroy the Party?

I don’t. I believe that Cameron and in particular Osborne have always been more bullish than most commentators about how much they could secure from the EU.

Indeed I think there is still an outside chance they could secure some changes (e.g. on the relationship between the Eurozone and the non-Eurozone EU) that would either be or at least would seem to them, to begin with, very significant. But I do not believe they have any illusions about their ability to carry the Party with them if they do not secure some significant deal.

I do not believe that Cameron would campaign to stay in the EU regardless of the deal he got from the EU. I believe he sincerely thinks he has chance of securing a major renegotiation, but that if he were not to get that (and as it happens I think the odds are against it) we should believe him when he says he rules nothing out.

The Prime Minister has secured a majority, is delivering the referendum and will now seek a renegotiation. Whilst he’s doing that we should give him the benefit of the doubt regarding his sincerity over the need to secure significant concessions if he is to campaign for us to stay In.