More than any previous election in modern times, this one seems to be a three horse race. The Lib Dems appear poised to improve substantially on their number of seats in the Commons, no party has a commanding lead in the polls and there is a strong possibility of a hung parliament in the United Kingdom General Election of 2010.

Such a scenario, in which no party has an overall majority, tends to amplify disproportionately the power of the third party, which then holds the balance of power, and with it, effectively, the keys to Number Ten Downing Street.

Is there anything the two major parties can do to defend themselves, and the interests of their voters, from a Liberal Democrat leadership in a position to make demands? Is there a way to level the playing field a little?

Well, yes. Actually, there is. David Cameron and Gordon Brown can form a pact.

I don't, of course, mean an agreement to work together in government. The rank and file of each party would tend to reject that rather firmly and such an agreement would be fragile indeed in the Commons. While both Labour and the Conservatives might be prepared, reluctantly, to forge a parliamentary alliance with the Lib Dems, they won't do so with each other.

No. I mean an agreement, drawn up secretly and witnessed by senior members of each party, detailing a list of policy points which neither party would be prepared to concede to the Lib Dems. So for example, Cameron and Brown could agree that under no circumstances would either permit Britain to enter the Euro without a referendum. They could agree, say, that neither would be prepared to enact legislation to introduce proportional representation.

Because make no mistake, Nick Clegg's position in the event of a hung parliament will be strong indeed. Even with fewer seats than either Labour or the Conservatives, he would have greater negotiating power than either of his two other main party counterparts. The electoral triangle is not equilateral. He can work with either of the other two parties, but the Conservatives and Labour will never share power between themselves. Barring a vanishingly unlikely breakthrough on the part of one of the minor parties, if Cameron and Brown need to look for an ally in government, Nick Clegg's Lib Dems are the only show in town.

But with a carefully negotiated agreement in place between the two bigger parties, if Nick Clegg should come to chat to David Cameron next Friday, then when he (perhaps) offers to support a Conservative government in return for abandoning Trident, Cameron can turn him down politely, assured in the knowledge that he won't get that concession from Brown either.

Shouldn't the two major party leaders be thinking about having a quiet chat in their mutual interest sometime in the next few days?

A badly edited version of this piece appeared in the Leicester Mercury newspaper on Thursday, 29th April 2010 and can be seen online here