Last night several senior Lib Dems tried to explain to me this strange proposal about 55% of the Commons being needed to bring down the government. I think the argument went that it only needed 50% plus 1 to bring down the government, but would need 55% to dissolve parliament. Or it may have been the oher way round.

I can see that dissolving parliament and bringing down a government are clean different things. Fixed term parliaments was a chartist demand – indeed they wanted annual ones. But the current abiity of a Prime Minister to call a general election when it best suits them plainly hands an unfair political advantage to the executive. So I have always supported fixed term parliaments of four or five years. But then even 100% of MPs, let alone 55%, should not be able to change the term and call an election when they feel like it. The term should be fixed and the MPs should have to get on with it – as in most democracies.

As for bringing down a government, plainly by definition a government which loses a confidence or supply vote, being opposed by 50% plus one members of the House of Commons, does not enjoy the confidence of the House and should fall. If you have a fixed term parliament you then need a different governrnent drawn from the same House.

Of course, we have a sovereign parliament. If a parliament votes for a 55% threshold, there is no means of enforcement. A future parliamentary vote, even if carried by precisely 50% plus one, to abolish the 55% threshold, would abolish the 55% threshold.