General Election 2015: could we be heading for a grand coalition?

Let's get this clear. What follows is not a prediction. I doubt it will happen. But it might; and if it does, the consequences for the future of British politics could be far-reaching.

I, and others, have been musing recently on the possibility of a messy outcome to the coming general election—that is, one where neither Labour or the Conservatives can win a secure majority, even by forming a coalition with what's left of the Liberal Democrat contingent of MPs. What role might the SNP play? Or Northern Ireland's Democratic Unionists? Or even Ukip, if it wins enough seats?

What's common to most messy outcome scenarios is that the resultant government is likely to be weak—with either David Cameron dependent on the goodwill of anti-EU Tory backbenchers or Ed Miliband relying on consistent support from Alex Salmond. The chances of such a government lasting five years are pretty slim. Thus the talk of a second election, either later this year or next year.

(Yes, I know the law says we now have fixed-term five-year parliaments; but there are ways round this if the Prime Minister of the day is thwarted on major issues.)

My question is: what happens if a second election produces an equally messy result? I suspect the pressure will mount—from voters, the media, business, the financial markets—for our politicians to find a way to put a government together that will last. Which brings me to my possibility-that-isn't-a-prediction: the simplest route to a majority government with a secure majority could be a grand coalition between Labour and the Conservatives.

Yes, I know all the reasons why this could be a bad idea. What on earth would a joint Labour-Tory programme look like—on taxes, Europe, the public services and so on? Surely the precedents are worrying? The last time this was tried, in 1931, almost destroyed the Labour Party. Isn't there a danger that either or both of the main parties might split? And what about the risks to both parties when they have to take unpopular decisions? Grand coalitions in other countries have often given a boost to fringe parties on the Right and Left.

On the other hand, would a few more months of weak government, possibly leading to a third election, be any better? Might voters turn away from Labour and the Tories in even larger numbers if they are seen to put party calculation ahead of the national interest?

Maybe you see an easy, popular and effective alternative solution to the problems we—voters as well as politicians—will face if we have two messy election outcomes in a row. I can't. Which is why some sensible MPs in both main parties are very privately pondering the possibility of a grand coalition at some point in the next year or two. They are right to do so—and wise to be very careful in choosing with whom to share these thoughts.