There has been much speculation in recent weeks about the possibility of the opposition parties and ex-Tory refuseniks coming together to oust this government and install an interim government, tasked with a very limited role of negotiating an Article 50 extension, promptly followed by a GE. (A variant of this proposal would have the interim government stay in office long enough to call a second EU referendum, but that seems vanishingly unlikely).

Like many suggestions for resolving the impasse, this one immediately runs into difficulties. The first problem is who would be the interim Prime Minister. Jeremy Corbyn thinks it should be him, but hardly anyone outside Labour agrees. To have any chance of getting the necessary cross-party support, including the support of ex-Tories and those who left Labour precisely because of Corbyn, a far less divisive and extreme figure would be required. Ideally this should be someone with experience of government, and who has no political ambition for the future. Margaret Beckett has been tipped as one possibility, or perhaps Ken Clarke or Harriet Harman. Whether Jeremy Corbyn would support an ex-Tory PM, or ex-Tories support a Labour PM backed by Corbyn, is a problem which itself might scupper the idea.

Let’s assume, though, that that difficulty can be overcome and a potential PM agreed. In all the speculation about possible choices for PM, hardly anyone seems to have noticed that a government is more than a PM. It needs ministers as well. Admittedly, this short-lived interim government would not be developing policy, or introducing legislation, or making long-term decisions, but that doesn’t mean that it wouldn’t need a skeleton ministerial team. Just as in the ‘purdah’ period after an election has been called, sometimes ministerial direction or the formal legal authorisation of ministers is indispensable. Although many minor ministerial posts and even some important Cabinet posts could be left vacant for the few weeks of the interim government’s existence, it would still need a Chancellor to sign off financial measures and to deal with any market or banking crises, as Alastair Darling had to in 2010. It would need a Home Secretary to be available to take action if there were a sudden terrorist atrocity or other emergency. It would need a Defence Secretary for similar reasons, and a Foreign Secretary to provide continuity in our relations with other countries. It would need a Lord Chancellor, and an Attorney General. In the current circumstances with Stormont suspended it would definitely need a Northern Ireland Secretary.

One can easily play Fantasy Cabinet Formation and put some names to these posts from those who supported the Benn Act. Phil Hammond or Ken Clarke could easily step up as temporary Chancellor, as could David Gauke, Yvette Cooper, or Vince Cable. The problem, though, is that the parties setting up this interim government would need to agree on dozens of such ministerial appointments, each one highly charged politically.

How likely is that, and how would the posts be divvied out? If Jeremy Corbyn were to agree on, say, Ken Clarke as PM, would he in return demand that John McDonnell becomes interim Chancellor? Or if the PM is a Labour figure, would Corbyn really be prepared to give his support to an ex-Tory Chancellor? Would the LibDems insist on Jo Swinson being in cabinet? Each appointment would become a complex multi-party negotiation amongst politicians who don’t trust each other.

This looks like one of those ideas – like Brexit itself – which looks more and more impractical the more you look at the details.

Richard Nabavi