Having made the mistake of learning about the Conservative Party’s rules, because I’m cool like that, it falls to me to try to cut through the confusion and counter-claims about the whole question of what happens when a Conservative MP loses the Whip.

There’s a whole separate debate to be had about whether the Government is right or wrong to threaten to take such action against MPs who vote against them tonight. We’ve covered that elsewhere: I took a look yesterday at why it’s not really accurate to compare a rebellion on an issue like this with more day to day rebellion, while Paul looked this morning at some of the risks, moral hazards and political consequences of the threat.

Rather, this article is just a look at the facts of the process.

First, as I explained earlier in the year – when covering Nick Boles’ dispute with his local association in Grantham – there isn’t really a ‘deselection’ process in the Conservative rulebook. Rather there’s a readoption process for sitting MPs, which they can fail to pass or which can be obstructed in some way. I know that might seem like a fine distinction to draw, but it does matter: it means that being ‘deselected’ is a negative process, failing to clear the requisite hurdles to keep candidate status, not a separate process of its own.

Normally, what’s termed deselection is a constituency event. An MP seeking readoption has to apply to their association executive to do so. They get the chance to present their case to the exec – what they’ve achieved for the constituency, what their plans are, what crucial work they do in government and so on – and then there’s a secret ballot. If they lose, the MP has the fallback options of going to a ballot of the whole association membership or automatically inserting themself onto the shortlist in the ensuing selection meeting. If they win the executive’s approval in that initial vote, however, they’re readopted and that’s normally it.

It’s at this point that things have become confused this week. The Government’s plan to remove the Whip from MPs who rebel tonight was characterised as “deselection” but nobody quite seemed to know why that was the case. In practice, the rulebook reasons why that would be the effect are quite straightforward. To enter the readoption process, you have to be “a sitting Member of Parliament”, and the party constitution defines that as “a Member of the House of Commons in receipt of the Conservative Whip”. So lose the Whip, and you lose your eligibility to be considered for readoption.

It gets a bit more confusing in one case. Philip Hammond – one assumes not coincidentally – managed to get his executive to vote on his readoption last night. They approved him. Some have taken that to mean that it is too late to deselect him by removing the Whip. Certainly Hammond himself claims to believe that, and has promised “the fight of a lifetime” against any attempt to do so.

Unfortunately, I simply think he’s got the rules wrong on this. He was readopted last night, perfectly validly, but that’s not an unassailable, inalienable status. If he loses the Whip tomorrow, effectively ceasing to be a member of the Conservative Party’s Approved Candidates List, then he would cease to be eligible to be nominated as the official Conservative candidate come election time. If Hammond claims that it is against the rules to effectively undo a selection after the fact, he needs to consider what happens when a non-MP Conservative candidate is suspended from the Party in some pre-election scandal: they wouldn’t have the right to insist on being the candidate because of the selection; the selection has been superseded.

The former Chancellor’s threat of “the fight of a lifetime” might “possibly” extend to a legal case, but if the constitution’s explicit rules aren’t sufficient to settle that (and they appear to be to me), the constitution also contains two clauses which make it implicitly impossible for him to prevail. Schedule 6, point 8, empowers the Party Board’s Committee on Candidates to establish any set of criteria it likes for membership of the Approved List. Schedule 6, point 13, empowers the Board and the Candidates Committee to “publish mandatory rules as to the procedure by which Constituency Associations and other bodies select Candidates for all or any public elections” whenever and however it likes. In short, if what they want to do isn’t covered to their satisfaction elsewhere in the constitution, they can write a binding policy making it so.

If that seems a remarkable degree of centralised and unchallengeable power, that’s because it is. Those Schedule 6 powers were used to establish the controversial selection rules used in the dash to select before the 2017 snap election, and even two years after I reported it people still seem surprised to learn that it really does work on the basis that the Party sets whatever rules it wants for itself.

If all those powers weren’t sufficient, and an association still wants to hold out to try to hang onto its candidate, then the Party Board has the power (under Part VII, points 49-53 of the constitution) to place the association into ‘Supported’ status, which amounts to central control. In short, this is not the localised, association-controlled party of 30 years ago. Nor has it been for quite some time.

Finally, when election time comes round, if for whatever reason Hammond and his association still tried to submit nomination papers, a national party must licence local candidates to stand on its ticket. A compliance message from CCHQ to the local Returning Officer making clear he was not their party’s candidate would suffice to prevent the nomination being valid under the Conservative Party name.

I’m aware the above is all rather technical, so here are three examples which illustrate the process in practice.

Howard Flight, 2005. As a sitting MP, Flight lost the chance to seek re-adoption when Michael Howard removed the Whip (for the comparatively minor sin of saying something about fiscal policy the leadership found embarrassing). His association tried to refuse to select someone in his place, as the 2005 General Election approached, but backed down when threatened with Supported status, preferring to begrudgingly find a successor of their choice than have one of CCHQ’s choice forced on them.

Adrian Hilton, 2005. A week before Flight got into trouble, Hilton was deselected by the Party leadership as candidate for Slough. The association stuck to its guns, and was duly taken over by the edict of the Party Board, which selected on its behalf. Hilton challenged the decision in the High Court and lost, with the court finding that the Party’s constitution does indeed allow the centre to set whatever rules and act on whatever basis it likes.

Alex Story, 2016. When Timothy Kirkhope entered the House of Lords, he ceased to be an MEP – meaning the seat would automatically transfer to the next candidate on the list. However, Story – the natural successor – had since been (unfairly) removed from the Approved List, and so the Conservative Party advised the Returning Officer for Yorkshire and the Humber that he was ineligible and the seat would go to somebody else, who had been further down the running order. Story, understandably incensed, challenged the verdict in court, only to also fall foul of the constitution’s provisions for the Party to do as it wishes.

In brief, Hammond’s readoption last night is not binding, and doesn’t prevent him being deselected by the loss of the Whip. Neither he nor his association has the ultimate say over his candidacy. And if the published rules as they stand aren’t sufficient to make all that the case, the Party Board has the power to write the rules however it feels necessary to make it so. And so far as I can recall, the court case record for the Party in such disputes is a merciless clean sweep.