David Maddox: Question - When is a principle a non-principle? Answer - When it's a Lib Dem principle

The Lib Dems have dropped their demands for a 2p reduction in income tax in the Scottish budget.

This is after months of their chief whip Mike Rumbles (pictured top right) corridors of Holyrood berating opponents for denying their constituents a tax cut.

The volte face also completely torpedoes their economic strategy as well as their 2011 election strategy. The idea was that they would sell themselves as the party which would leave more money in people's pockets.

Lib Dem leader Tavish Scott (pictured left from his days as a mad viking) hinted at the change on the radio this morning, but senior colleagues have now briefied journalists to confirm it.

So what has changed?

Well, after yesterday there is a new budget to fight for and the Lib Dems see the chance of influencing it. Mr Scott and his finance spokesman Jeremy Purvis have meetings scheduled with Finance Secretary John Swinney this afternoon.

The irony in all this is that the Greens, who in a fit of pique brought the budget down yesterday when they had all but won £33 million in next year's budget to start their free insulation scheme, may now get muscled out by the Lib Dems and get nothing.