John Daly of the U.S. plays a shot on the 15th hole during the second round of the British Open golf championship at Royal Lytham & St Annes, northern England July 20, 2012.
The economy grew 0.4% quarter-on-quarter and 2.1% compared to the same period last year.
The original estimates were 0.5% growth on the second quarter and a 2.3% rise on the third quarter last year.
It's another piece of disappointing data for Chancellor George Osborne this week Public sector borrowing came in well above forecast at £14.2 billion for November. That's means Osborne is almost certain to miss the country's borrowing forecast for the year.
Despite the downward GDP revision and the likely missed borrowing target, Britain is in an economic sweet spot right now, with rock bottom levels of unemployment and growth looking on track.