The Coalition has been much more of a success than anyone could have predicted when it formed in 2010. It hasn’t just held together for spending cuts, but has passed important reforms to welfare and education. It’s important to repeat that now, when the partnership is growing increasingly tired and snappy. The parties spent yesterday pecking at one another over whether or not to introduce tougher mandatory sentences for repeat knife offences. They won’t produce a Queen’s Speech bursting with legislative excitements, either.

But one of the things that this Coalition has shown us is that it’s not just the policy red lines that make a difference to whether a government of more than one party can be radical: it’s the plumbing too. And one important piece of plumbing that the Conservatives don’t seem to have fully understood the implications of when it was put in place is the Home Affairs Committee.

As I write in my Telegraph column today, some Conservative ministers and advisers would very much like it if Nick Clegg does not continue to chair this influential cabinet committee if the two parties find themselves manacled together again after the 2015 general election. The trouble is, Clegg would likely want to hold onto this job above all others, as it gives him so much power.

Some Conservatives had already decided that the only way they could do what they thought was right was to effectively burrow under the fences that Clegg put up on this committee. Dominic Cummings, who was until recently Michael Gove’s adviser in the Education department, tells me that:

‘Gove’s team could not have accomplished all it has unless it had flouted the Whitehall rules and ignored the Home Affairs Committee against the wishes of Downing Street.’

This certainly sent the Lib Dems into a spin at the time: Clegg and Cummings recently enjoyed a rather fabulous war of words in the press. But it also sent civil servants into a tizzy too. And as the Institute for Government argued this week, Whitehall officials would very much like more guidance on how to work with two parties that are increasingly pulling apart in the run-up to an election. But if there’s another coalition between the Liberal Democrats and the Conservatives, those civil servants will need to deal with two parties bearing grudges who increasingly try to break the rules if Clegg holds onto his prized HAC job.

Tags: Coalition, Conservatives, Lib Dems, Queen's speech