The 55% rule on dissolution is the stitch up of the century but it strikes me that it is evident that the people who put this together and are now in government are, how should I put this, a bit stupid? The relevant text in Con Lib deal goes as follows:
The parties agree to the establishment of five-year fixed-term parliaments. A Conservative-Liberal Democrat coalition government will put a binding motion before the House of Commons in the first days following this agreement stating that the next general election will be held on the first Thursday of May 2015. Following this motion, legislation will be brought forward to make provision for fixed term parliaments of five years. This legislation will also provide for dissolution if 55% or more of the House votes in favour.
In a well argued piece by Louise Balldock it is clear that they the Tories are trying to make it impossible to oust them from Parliament even if the coalition falls apart, they alone could put up more than 45% of the votes, rejecting dissolution.
But this is the stupid bit. They can’t rig votes on bills, so if the coalition does fall apart and there was a majority in favour of dissolution all they would have to do is vote through an amendment to this crass Act restoring the principle, up until now delivered through convention after the passing of a motion of no confidence, of a simple majority for dissolution. Makes you despair.
Ballot Blogs 
What? The whole point of adding in this clause (which is normally more like 66%, like in Scotland and Wales) is to make the fixed term parliaments actually fixed term.
This is the problem with letting the legislature modify the constitution at all, but is certainly not undemocratic – it just means that a new coalition must be formed to limp through the rest of the 5 years if the first one falls apart.
Of course a majority could modify this if they want to – but there should surely be some rule requiring more than 50% +1 majority to modify the constitution like this (although parliament isn’t allowed to pass anything restricting future parliaments, so you couldn’t do that through parliament).
It’s all just part of having a more grown up constitution in which coalitions are possible (i.e. under which parties can trust their coalition partners not to walk out on them early.) We need a more open, mature, coalition based electoral system anyway.
There’s a groundswell of opinion that agrees with you but I think this article in Next Left sums up the view that this is a tactical rather than strategic initiative and is about overturning conventions in the constitution as a means protecting a minority Conservative administration. How else was arbitrary figure of 55% reached?
http://www.nextleft.org/2010/05/libdems-destroy-defence-of-55-rule.html
This article misses the point. You still only need 50.1% to force a change of government via a “no confidence” vote -> then opposition parties can negotiate to form a new coalition. This is all about trying to have fixed terms.
The 55% is solely to do with forcing a general election and is there to prevent the Conservatives pulling a fast one on the Liberal Democrats.In Scotland it’s at 66% as it assumes that one party could have a majority and doesn’t want that party to have the power to control when the next election is.
I don’t entirely disagree, but it muddys the waters between no confidence that has traditionally been followed by a dissolution and voting to end a fixed term. The core point here is that unless there is a subsequent act on the constitution it can be easily overturned.
Well I agree it’s caused confusion but this is because we don’t currently have fixed term parliaments – it’s alien to us.
Your point about it being overturned is certainly valid, but applies to any law since we don’t have a written constitution. Some argue that it is issues such as this that mean we should!
Parliament does not currently have the right to vote for a dissolution anyway. No confidence is not the same thing.