Thank you Ed Balls and Peter Hain for reinforcing the Conservative message

There has been much discussion across the media today about the pleas for anti-Tory tactical voting by Ed Balls and Peter Hain this morning - and it seems Tessa Jowell has now joined in as well.

These Cabinet ministers are counselling Lib Dem voters to back Labour in a bid to stop Conservatives from being elected in seats where the Lib Dems have no chance of winning, and effectively telling Labour voters to back the Lib Dems in seats where Labour is in third place - such as Norfolk North, as Ed Balls suggests.

But I wonder whether they may yet come to regret these last ditch interventions: Labour are attempting to play them down, and I don't doubt that Nick Clegg will not be thanking them for one moment.

For what they have done is to reinforce the Conservative message that if you want Gordon Brown and Labour out of office, then the only way to ensure that happens is to vote Conservatve.

The Lib Dems have been trying to claim that they offer change, but they have refused to rule out propping up a Labour administration; and now you have the message being conveyed by these senior members of Brown's adminstration that in Parliament Labour and the Lib Dems are interchangeable peas out of the same pod.

Incidentally, the very notion that tactical voting can only work against the Conservatives has now been blown out of the water.

On today's World at One programme on Radio 4, ex-Labour minister Lord Gilbert called on Labour voters to vote Conservative as a tactical move against the Lib Dems in seats where Labour is in third place because the Lib Dems would be irresponsible when it comes to "defence of the realm".

On the same programme a Lib Dem sympathiser in the Labour marginal of Tooting was interviewed saying that he would vote Conservative to oust the sitting Labour MP.

And when it comes to the political instincts of Lib Dem voters on the ground these days, it is also worth looking at the London mayoral election result from 2008. Of those who voted for Lib Dem candidate Brian Paddick who used their second preference vote, they split virtually 50-50 between Ken Livingstone and Boris Johnson.

Jonathan Isaby