Jill Kirby: A Cleggeron Coupon? Lessons from history

Is next week's contest in Oldham and Saddleworth a "coupon election" in all but name? David Cameron may not have offered the LibDem candidate a formal endorsement, but it is clear he would not be unhappy with a LibDem victory. So perhaps this is a good moment to draw a few comparisons with the 1918 Lib-Con coalition campaign, in which the coalition partners (Liberal Prime Minister David Lloyd George and Conservative leader Andrew Bonar Law) issued a letter of endorsement to pro-coalition candidates (159 Liberals and 364 Conservatives).

• The coalition duly won the election.
• The coupon enabled the parties to avoid a merger and to maintain separate party identities - but provided a formula to ensure that they did not campaign against each other
• It was driven by the party leadership and tolerated by the (largely submissive) rank-and-file
• The fact that the election took place in the immediate aftermath of war meant that the party could claim to be pulling together at a time of national hardship
• Political historians point out that Lloyd George's motive was his ambition to create a centrist party to dominate British politics.
• But the resulting split in the Liberal party was to destroy them as a political force.

So what might a coupon do for the Conservative and Liberal parties at the next general election?