Labour is still pursuing its mansion tax vote, with the debate set for next Tuesday. It's a clever piece of political timing by Ed Miliband's party, as the text of the motion is now out and about in time for the Lib Dems to assemble in Brighton for their Spring Conference. Vince Cable is speaking tonight at a fringe event, and will undoubtedly be asked whether he wants the Lib Dems to support it. The motion, which the party has just released, reads as follows:
'That this House believes that a mansion tax on properties worth over £2million, to fund a tax cut for millions of people on middle and low incomes, should be part of a fair tax system and calls on the Government to bring forward proposals at the earliest opportunity.'
This is very carefully-worded indeed. It does not mention the reintroduction of the 10p rate that Labour wants to use the mansion tax for. This means it will be more difficult for the Lib Dems to vote against it.
What Labour would like to do would be to cause chaos in the Coalition on this. It's not so much that it would upset the Lib Dems internally in the way that supporting Mark Reckless' motion on the EU Budget upset the Tory party internally. The Lib Dems have, all the way up to the leadership, been openly campaigning on the mansion tax. The weirdest example of this is the official party petition a few months ago which came from Vince Cable and was sent to the Treasury: an example of a minister lobbying his own colleagues on a policy they'd already rejected.
The Social Liberal Forum also has an emergency motion on the economy which calls for a mansion tax. If the motion is selected, it is likely that activists will push the Lib Dems to stand up for their treasured policy in the parliamentary vote.
But the real problem that this will cause is that if the Lib Dems do decide to vote with Labour on their motion, the Tories will get very upset. There are many MPs, and not just Peter Bone, who are irritated by the way the Lib Dems think they can freelance on certain policy areas. After the Eastleigh by-election, Conservative MPs are feeling particularly tender about the boundary changes after the Eastleigh by-election, as the scale of their struggle for 2015 is becoming even more obvious. They might have expected the Lib Dems to vote with Labour if they'd lost the Eastleigh contest, as a way of cheering themselves up. But they will be less sympathetic with the victorious party doing its own thing on a central issue such as tax policy.
But if the Lib Dems do vote for this motion, they will then face caterwauls of 'hypocrisy' from Labour when the Finance Bill goes through parliament, as Ed Miliband can say they vote one way or another as often as the wind changes.
One way they could neutralise this would be to introduce an amendment to the motion, written by Cable or Danny Alexander, which has its own Lib Dem flavour, possibly referring specifically to the rise in the personal allowance rather than a vague reference to 'a tax cut for millions of people on middle and low incomes'. Whether they do depends on how much of a fight they want just a few weeks before the Budget.