Economic growth and Ed Miliband will save David Cameron's leadership... but they won't be enough for victory

By Tim Montgomerie
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There are stories in this morning's newspapers about Boris Johnson possibly returning to parliament before 2015 and challenging Cameron. I've blogged previously about how this might happen. I've also said that there's only a 20% chance of David Cameron being ousted as Tory leader before the next election. A year ago I would have only given it a 1% chance but that was before the Coalition descended into its paralysis of the last six months. This last week, however, we've seen some early signs that this paralysis might - just might - be being overcome.

As well as the difficulties of Boris becoming an MP before 2015 - or of another alternative Tory leader emerging - there are also the huge practical obstacles inherent in a disputed contest. And the contest will certainly be disputed. SteveHiltonGuru has set out the contours of that dispute. Compared to 1990 when Margaret Thatcher was ousted - the last time the Conservatives took the enormous step of removing a sitting PM - there are two big differences:

1. Difference one is that we are in Coalition. Will the LibDems simply sit quietly by and allow the Conservatives to change leader and PM, with all the possible consequences for the content of the Coalition Agreement? You can be sure that any wannabe Tory leader would be standing on a distinct manifesto.
2. The second difference between now and 1990 is that the nature of the Tory leadership election process has changed. Once the parliamentary party had toppled Margaret Thatcher they chose John Major within about a week. Any successor to David Cameron would have to be chosen by the whole (diminishing) Tory grassroots membership. That would take two to three months and the Government might struggle to take big decisions while it was underway.

The party would only reach for the nuclear button if it was in desperate straits and it'll be 12 to 18 months before any sensible person should conclude that we are in such straits. My guess is that there is a 20% possibility of complete Coalition breakdown and Tory poll ratings getting much worse than they are now. In sharp contrast there is an 80% possibility that the two preconditions of Tory recovery will be in place. Those preconditions are that the economy is growing noticeably by 2014 and that Ed Miliband (whose ratings remain on the floor) will still be Labour leader. That growth might be sluggish and Ed Miliband might yet improve a little but those two factors combined will be enough solidify the Tory standing in opinion polls and will keep hope alive on the Conservative backbenches.

Those two things will, unfortunately, also be inadequate to get the Conservative Party to the 7% to 10% lead in the opinion polls - which is what we need for a majority. Cameron will survive, therefore, but he'll need much bolder moves to turn survival into an election-winning victory.