Windfall tax

[AtW]

Is there a precedent for a windfall tax?

Plenty - most recently I think it was done by certain Mr Brown, whose windfalling taxation resulted in decrease in investment into the North Sea, which finally resulted in decrease in gas extracted from there thus making UK less self-sufficient on its own resources...

[Peoplesoft bloke]

Is there a precedent for a windfall tax?

Conservative Chancellor Geoffrey Howe imposed a Special Tax on Bank Deposits in the 1981 Budget. He justified the tax because an increase in interest rates had resulted in the main clearing banks making higher profits.
The tax was levied at a rate of 2.5% on banks' non-interest bearing current account deposits above a minimum threshold and, according to the IFS, raised £350 million (approx £700 million in 1996-97 prices).