Public Expenditure As % Of GDP
Public Expenditure (Total Managed Expenditure) is currently around 42% of GDP, up from 38.9% in 1997-98. The government forecasts an increase to 42.4% in 2008-09, a 3% increase under Labour.
Under the 1979-97 Tory governments, spending was reduced by about 5% of GDP, a substantial achievement.
The IFS have an excellent briefing note.