Democratic Audit UK has a good discussion of the issue of fixed terms for the UK House of Commons, which were legislated by the current coalition government that took power following the 2010 election. A group of Tory backbenchers has proposed doing away with the 2011 Fixed Term Parliaments Act.
With a single-party majority in 2015 looking unlikely, it is not surprising that many Conservatives would prefer a return to the old pattern whereby a minority single-party government would just bide its time till things looked promising for going to the polls and potentially securing a parliamentary majority. (As I have noted in the recent past, there are such attitudes present in Labour Party quarters, as well.)
Arguments given by supporters of repeal are that MPs are more accountable when elections could come at any time and (predictably, given the source) that fixed terms give the junior partner in a coalition too much power. In the event of a future coalition, the supporters of repeal suggest there could be a “gentleman’s agreement” that the coalition should end only when both parties wish it to end. (Isn’t that precisely that the Fixed Term Parliaments Act was for? To make sure the “gentlemen” could mutually police their agreement?)
Democratic Audit’s editorial offers a series of reasons why keeping fixed terms is preferable. This was a matter that was discussed in a couple of threads here (#1, #2) at the time. What do readers think now?