Jonathan Isaby: Are the Liberal Democrats seriously saying they would prop up a Labour government?

The very last outcome that the country indicated it wanted at the general election was a coalition between Labour and the Liberal Democrats.

The public will be startled at the idea that the Liberal Democrats may allow a party so comprehensively defeated at the polls to remain in government – and under a second unelected prime minister in a row. Would it not be a supreme irony, after all the excitement of the prime ministerial television debates, for the person who ends up in Downing Street to not have actually taken part in those debates?

It had all seemed to be going well yesterday: the talks between the Conservatives and Liberal Democrats continued apace and the messages coming from both negotiating teams seemed to be extremely positive. The rumours circulating around Westminster were that a deal was in the offing.

Then came the bombshell that the Liberal Democrats had opened official coalition negotiations with Labour and that the Prime Minister was to resign as Labour leader.

The Conservatives learnt with some considerable degree of surprise that Nick Clegg believed he might want to try to ride both horses at once.

If this is merely a tactical move on Clegg's part to seek further concessions from the ongoing negotiations with the Tories, it is unlikely to be successful. The Conservatives have bitten the bullet of offering the Liberal Democrats a referendum on the alternative vote system and that will clearly be their final offer on voting reform.

The only other possibility is that the Liberal Democrats are now seriously countenancing trying to prop up a discredited Labour government which came off worst at last week's general election.

The voters' verdict was not as clear as it might have been, but one thing was for sure: they showed their desire for Labour to be ejected from office by sacking the best part of 100 of their MPs (sending fewer Liberal Democrats back to Westminster too).

This hung parliament is very much the exception to the rule. First-past-the-post has in the main delivered a decisive result, with a prime minister re-appointed or turfed out within hours of the ballot papers being counted.

In their insistence on proportional representation, the Liberal Democrats wish to institutionalise the very confusion and chaos which we are witnessing.

They want to ensure that no party ever wins a Commons majority again. They want to make the last few days' double-dealing, backroom negotiations and associated uncertainty a fixture after every future general election. And they want to create a system whereby no party could ever seek to implement its programme as manifestos would merely become a list of aspirations ready to be sacrificed in an inevitable post-election negotiation.

So the Liberal Democrats now have a choice. If they go ahead with the plan to keep a weak, unstable Labour government in office, they will – whatever the electoral system – pay the price at the ballot box next time voters go to the polls.

The writer is Co-Editor of ConservativeHome