The U.K. economy faces its worst performance since the 1990s recession before an election that Prime Minister Gordon Brown must call by 2010, forecasts by the National Institute for Economic and Social Research show.

Britain's gross domestic product will rise 1.5 percent this year, 1.4 percent in 2009 and 1.9 percent in 2010, said the London-based group, whose clients include the Treasury and the Bank of England. That would be the worst spell since the three years through 1992.

GDP growth is expected to be relatively anemic over the next three years, Niesr economist Simon Kirby wrote in a report published today. We see a modest slowdown rather than any recession, he told reporters.