Who's at most risk from Clegg?

Spooked by the Lib Dem surge over the last two weeks, both Labour and the Conservatives have rushed to spook voters thinking of voting yellow on May 6th. Flirt with Clegg, say Labour, and you end up married to David Cameron. Vote Clegg, say the Tories, and you'll wake up with Gordon Brown in Downing Street on May 7th.

Both Labour and the Conservatives are trying to spook voters away from the Lib Dems. There aren't many facts, it all hinges on impossible calculations and predictions, but it does seem clear that the Lib Dem surge should hold until polling day. They're holding steady at around 29% in national polls. But the polling figures also show that of those who are saying they will vote Lib Dem, 27% say they may change their minds. Labour and Conservative voters are more decided, with only 15% saying they may change their minds.

So what do you get if you vote Clegg? Perhaps the right question to ask is which of Labour and the Conservatives has the most to lose from the Clegg surge?

The big worry for the Tories is that a Lib Dem surge puts out of reach the 30 Lib Dem / Conservative marginal seats that Cameron needs to win to tick off the easiest of the 118 seats required for an overall majority. The Tory strategy has long been based on winning the vast majority of these Lib Dem seats. It now appears likely that the Lib Dems will hold the vast majority of those seats.

For the Tories, this is a major headache. It means that Cameron now has to win seats outside his target list of 118. It means Cameron needs to win harder Lib Dem seats requiring even greater swings and Labour seats, many of which are in the North. And the figures for the Tories in the North don't look good. Labour may be behind in the national polls (and collapsing in the South at 17% of the vote), but the Labour vote is holding up in the North at 40% compared with Mr Cameron's 24% (the Lib Dems are a steady 29%). Seats such as Leeds North East and Ellesmere Port near Liverpool look unlikely to fall to the Conservatives given their current regional projections. The Tories are realising this, claiming rather transparently that they were "extending the battleground" to Labour held seats outside their target list of the most winnable seats. It represents a major change in tactics for a party that has poured money into around 130 target seats since at least 2007.

The Lib Dems threaten the Tories everywhere, looking likely to hold on in the Conservative / Lib Dem marginals and taking away valuable votes in the North with a healthy share of the vote. Crucially of all the parties, the Lib Dems have their support spread evenly across the country, with 32% support in the South and Midlands and just 27% their lowest vote share in London. Labour on the other hand crash to 17% in the South, but soar to 40% in the North. The Tories hold firm at 40% in the South, Midlands and London, but have their own crash to 24% in the North.

There is a chance that the Lib Dem surge may help the Tories in the North. If Labour leak votes to the Lib Dems and Tories in equal measure, in some seats it may let the Tories in if they're already in second place. But if the Tories don't make in-roads to the Lib Dems in the South, then it will be serious squeaky-bum time for Cameron in the North. My hunch is that he will do better than some expect outside the Tory 118 seat comfort zone, winning seats as far down the list as the 150s... but that the strength of the Labour vote will leave Cameron just short of his overall majority.

Of course, the Tories are being noisiest about the dangers of a hung parliament and of voting Clegg. The IMF will be called in, they say. You'll wake up on May 7th and Gordon Brown will still be here. None of the disaster scenarios spelt out in the Tories rather panicky (and riskily negative) election broadcast this week will come to pass.

For Labour, the danger is not so much Vote Clegg, Get Cameron. The danger is if too many vote Clegg, you get Labour meltdown. But it's a tricky balance. They know that the more who vote Clegg, the more likely their best scenario - a hung parliament - will be. No serious Labour Minister could have expected to win this election. From the start, they have been in John Major "damage limitation" mode. The size, or lack of, Cameron's majority matters greatly to them. But coming third in share of the vote and matching the depths of Michael Foot's 28% after his "longest suicide note in history" is seriously bad news for the Labour recovery post May 7th. It may even deprive them of the right to be Her Majesty's Loyal Opposition. They will want Clegg to do well, but not too well.

PREDICTION: Hung Parliament - Conservatives short by 5