Two years on from their famous love-in at the Downing Street rose garden, David Cameron and Nick Clegg have chosen the appropriately sober setting of an Essex factory for their post-election "relaunch". All the talk is of the pair "renewing their vows" but that's not quite right. Cameron's betrayal of Clegg during the AV campaign meant that the marriage was dissolved long ago. It's not personal, it's just business, is the coalition's new mantra.

Despite Cameron's fear of his government being seen as a "bunch of accountants", the pair will insist that the coalition's raison d'être remains deficit reduction. As the PM will say:

Two years ago our two parties came together to form a strong Coalition. We agreed that our number one priority was to keep Britain safe from the financial storm and to rescue our economy from the mess left by the last Labour Government. That was and remains our guiding task.

But if deficit reduction is the coalition's "guiding task", it's worth pointing out that it hasn't been very good at it. The government borrowed £126bn in 2011-12, £10bn more than Osborne predicted in his "emergency" Budget, and the national debt is set to reach £1.4 trillion by 2014-15. Of course, it's hard to borrow less when the economy is shrinking. In this respect, the government's biggest mistake was to prioritise defict reduction above all else. As Keynes once remarked, "look after unemployment and the Budget will look after itself".

There will be some token references to growth in the speech, with Clegg promising a "renewed sense of urgency" and a "redoubling of our efforts" on getting more credit into the economy and building infrastructure. Yet the refusal of Osborne's "fiscally neutral" Budget to endorse stimulus meant that the real chance to boost growth was missed. Cameron and Clegg will insist that the damage done by the financial crisis was "greater than anyone thought" but to the voters, who have seen their living standards plummet at the fastest rate since the 1920s, this will just sound like another excuse.

Osborne's toxic Budget means that the pair can't even fall back on the old saw that "we're all in this together". Spying a political opportunity, Ed Miliband will also be in Essex today, calling for the reintroduction of the 50p tax rate and the repeal of the "granny tax".

The next election may still be three years away (although it doesn't feel like it, we're not even halfway through the coalition's term) but both parties already have their eyes on 2015. Two years ago, there was talk of a Tory-Lib Dem pact at the next election. Now, figures on both sides suggest that the coalition may not even make it that far. Today's Times (£) reports that the Lib Dems are considering withdrawing from the coalition "well before" May 2015 to allow the party to "reassert its independence". Given the scale of their losses last week (the Lib Dems now have fewer than 3,000 councillors, the lowest number since the party was formed in 1988), that's no surprise. As Matthew Oakeshott, Vince Cable's representative on earth, has warned, if the Lib Dems suffer more defeats like that one, they will not be able to fight the next election as a national party.