There was strong talk of a Labour-Lib Dem partnership at the IPPR fringe meeting I've just returned from. The former Liberal Democrat leader Ming Campbell declared that in the event of a Conservative victory his party would be compelled to work more closely with Labour.
"If Armageddon happened and we were faced with a Tory government, then the argument for increased co-operation with the centre left might not be a matter of choice, but a matter of compulsion," he said.
The conviction with which he spoke those words suggested that the same could apply in the event of a hung parliament, potentially leading to a coalition. He repeated his mantra that the party should aim for "maximum votes, maximum seats and maximum influence" at the next election (what else should they do?), but this now seems a mere formality.
It was notable that Campbell and his fellow panellists, including Labour's Charles Clarke and Shirley Williams (Vince didn't make it), repeatedly referred to the future of the "centre left" rather than their own parties. Clarke gently chided the Lib Dems for sometimes lapsing into "pure oppositionism" but argued that the differences between the parties, most obviously on civil liberties, could be thrashed out. All of the panel expressed their concern that David Cameron's European policies could leave Britain on the brink of withdrawal from the EU.
It's not surprising that, with the Conservative lead increasingly impregnable, thoughts should turn to a Labour-Lib Dem coalition. The two parties have consistently retained enough support between them to block the Tories from office. As Neal Lawson and James Graham write in their Guardian article today: "The combined votes of the two parties have averaged 55% since 1945; the Tories only 40%."
It's also now clear that Nick Clegg has abandoned the party's policy of "equidistance" between Labour and the Conservatives. In his recent Demos pamphlet, The Liberal Moment, Clegg may have argued that the Liberal Democrats could replace Labour as the leading progressive party, but in doing so he acknowledged that it was Labour, not the Tories, that had been a force for progress in recent decades.
In response, leading Lib Dems have intensified their attacks on Conservative policy. Chris Huhne's speech this afternoon was the most explicit sign of this yet. The party's home affairs spokesman declared: "Now that it's clear beyond doubt that Labour can't win, it's time for us to take the gloves off with the Tories."
He also delivered the most effective assault I've seen from a senior politician on Cameron's shameful alliance with Europe's reactionaries:
David Cameron says he cares about climate change, but then joins up with the Czech ODS that denies it exists. Cameron says he will stand up for gay people, but then allies himself with a Polish party of homophobes. He says he cares about human rights, but then cuddles up to a Latvian party that celebrates Adolf Hitler's Waffen SS. You can tell a lot about a party by the company it keeps.
Europe is one area where Labour and the Liberal Democrats should co-operate far more closely than they have done. It's understandable that the Lib Dems don't want to prop up an unpopular government, but it would be irresponsible of them not to come to the aid of progressive politics.