The coalition government has agreed to introduce fixed term parliaments - and with it, a new power for MPs to vote to dissolve Parliament. But it has been branded a "fix" aimed at keeping the Conservatives in power by opponents.
What is the row about?
It boils down to an argument about the way the new coalition government wants to bring in fixed term parliaments - and the mechanism it wants to introduce to allow Parliament to dissolve itself before the full five-year term is up.
So - the government is making it harder for MPs to dissolve parliament?
No. Currently MPs have no power to dissolve parliament. That is a matter for the prime minister, who asks the Queen to do so and can currently do so at any time of his or her choosing within a five-year term. New plans for fixed term parliaments will actually give MPs extra powers in that, if 55% of them back it, they will be able to dissolve Parliament.
So why the concern?
There seems to be a lot of confusion about what the government is planning - with even constitutional experts at odds over whether it amounts to a big change. Currently MPs can win a vote of no confidence - which you would usually expect to trigger an election if the government loses. That only requires a simple majority of MPs to back it - so 50%, plus one. But that will remain the same under the new plans, says the government.
What is the difference then?
Well, if the new rules are introduced we will have fixed term parliaments - so elections would be called on a pre-set date every five years, rather than at any point during the five-year cycle of the government's choosing. Under the new arrangement, it appears that should a government lose a no-confidence vote, it would not trigger an election. Instead the government could try to form a new majority government. However, under the current system, losing a confidence vote would not automatically trigger a general election either- it is still ultimately up to the PM to dissolve Parliament.
It all sounds rather confusing.
It is - people on both sides of the argument have accused the other of misunderstanding the new rules. This is perhaps because the rules, as such, are as yet only outlined briefly in the coalition deal drawn up between the Conservatives and the Liberal Democrats. Describing legislation to bring in fixed-term parliaments, the document says it "will also provide for dissolution if 55% or more of the House votes in favour". David Cameron has said the details will be debated in the Commons.
So, who's against it?
Labour heavyweights Jack Straw, Lord Adonis, David Blunkett and Lord Falconer have been scathing in their criticism. Mr Straw said it amounted to a "fix" and was "completely undemocratic and totally unworkable". Mr Blunkett said it was "nothing less than a stitch-up by the Conservatives and the Liberal Democrats to overturn historic precedents for their own advantage". Lord Falconer warned of a "zombie government" if ministers were defeated on a vote of confidence, but there was insufficient support for a dissolution. Conservative MP Christopher Chope said it was "unsustainable" and could be a "recipe for anarchy" if the government lost its majority. Backbench colleague Charles Walker said it was a threat to the "primacy of Parliament". And constitutional expert Prof Peter Hennessy said it looked like "very iffy politics" and created a "very poor impression for the new politics."
Are they right?
Former Lib Dem MP David Howarth, a legal academic who drew up the original Lib Dem plans for a fixed-term parliament, said the confidence vote and dissolution vote were totally different things and critics had got "entirely the wrong end of the stick". He said, in other countries with fixed term parliaments, if a government lost a vote of confidence the parties would have to try to work out a new government within the fixed term. Professor Robert Hazell, director of the Constitution Unit think tank, told the BBC all fixed-term parliaments had to have a "safety valve" to allow an early dissolution if necessary. He said, as he understood it, the 55% threshold was intended to prevent the government from calling an early election without the consent of both coalition partners - not to prevent an opposition move for a no-confidence motion. "It's not some constitutional monstrosity.. we already do this in Scotland." If First Minister Alex Salmond lost a confidence motion, he would resign - and that would happen in Westminster, he said.
What does the government say?
It says it wants "strong and stable government" with a "lasting coalition". A spokesman said fixed terms were a new idea for the UK Parliament, but were "perfectly normal around the world and require a mechanism for dissolution". He said in Scotland, two thirds of MSPs had to back dissolution - something created under the previous Labour government. He added: "The mechanism for a no confidence vote in the Government is unchanged but what our proposals would do is give Parliament a new power to dissolve itself, a power currently only exercised by the prime minister." MPs and peers will ultimately agree the proposals.
Why have a 55% threshold at all?
There has been some suggestion it was put in to stop either the Tories or the Lib Dems walking out on the coalition halfway through when their poll ratings pick up. But some argue it is not high enough as theoretically the Lib Dems and Conservatives could whip their MPs - who together reach just over 56% - to support a dissolution motion and subvert their own fixed-term parliament plan.
What happens in other countries with fixed-term parliaments?
Both the Scottish Parliament and Welsh Assembly have fixed terms with a "safety valve" - if at least 66% of MSPs or AMs vote for dissolution - or if they do not nominate someone to be first minister - they are dissolved and an election triggered. In Germany, dissolution in mid-term is allowed only in cases of serious deadlock - if the Bundestag does not support the chancellor on a motion of no confidence and does not to elect a successor within 21 days - it is designed to stop an administration deliberately engineering a no-confidence vote, as has happened twice.