Is Vince Cable's halo slipping again? The Lib Dems' national treasure's proposed levy on expensive homes appears to be unravelling.
Dr Cable's team say the charge - applied on the value of homes above £1m - is a UK-wide tax.
Oh not it's not say his friends in the Welsh Liberal Democrats. They say the Assembly Government - and the Scottish Parliament - would be able to opt out of a levy, the proceeds of which would raise tax thresholds across the UK, lifting the poorest out of income tax altogether.
Property tends to be cheaper in Wales, with fewer £1m-plus houses, so it's questionable how much the levy would raise.
The tax would apparently be based on land registry values - i.e. sales. So if you bought your home for £60,000 forty years ago and it's now worth £2m you wouldn't pay the levy.
It would also be temporary and apply only until a local income tax is introduced.
The charge has been described as a "mansion tax" although constituents of some Lib Dem MPs in south-west London could re-brand it as a "terrace tax".
Could this possibly be less a policy and another one of Dr Cable's famous "first, rough attempts"?
Presumably not, as the "framework of principles" underlying all Lib Dem tax policy includes "simplicity - tax policies should be clear to taxpayers and new policy should aim to eliminate complexity in existing legislation."
That's all clear then.