Britain's economic growth at the start of the year fell below trend for the first time since mid-2005, according to the National Institute of Economic and Social Research.
Growth in the three months to end-February was 0.5 per cent after a downwardly-revised 0.4 per cent in the three months to end-January.
Official figures show Britain's economy grew by 0.6 per cent in the fourth quarter of 2007 after 0.7 per cent in the third.
The Bank of England believes some degree of slowing is necessary to contain inflationary pressures. It held rates steady at 5.25 per cent this month after quarter-point cuts in both February and December.