Britain's recession is worse than the government expected and the economy is unlikely to return to growth at least until the end of the year, finance minister Alistair Darling said Sunday.
Darling will revise his economic forecasts lower when he presents Britain's annual budget on April 22, the Sunday Times reported.
He is expected to say the economy will contract by three percent this year -- its worst performance in a single year since World War II and three times the rate of decline forecast in the government's pre-budget report in November.
"It's worse than we thought," Darling told the newspaper in an interview.
"I thought we would see growth in the second part of the year... I think it will be the back end, turn of the year time, before we start seeing growth here."
Asked whether the worst was over for Britain's economy, Darling replied: "I think there is some way to go yet. A lot really depends on how much other countries do."
Britain's economy has been hammered by the international financial crisis and resulting global downturn, with unemployment soaring to a 12-year high as the country endures its first recession in 18 years.
Darling's comments came soon after Thursday's G20 London summit which announced a series of measures to boost the world economy including one trillion dollars for the International Monetary Fund (IMF) and other bodies.
He later urged caution over what could be achieved by the summit, despite Prime Minister Gordon Brown's description of it as representing a "new world order".
"It should not be understated (the agreement reached by the summit) but we should be realistic too," Darling, whose formal title is chancellor of the exchequer, told BBC television.
"We've got to make sure that everything we agreed is implemented on the ground -- that will decide the extent of the difference this meeting makes".
Asked about the report of a three percent contraction in the economy, he declined to comment on specific figures but highlighted concern over economic figures from Asia likely to hit British trade.
"If you look at what has happened, the downturn since last autumn has been far deeper than I think people expected in any part of the world," he said.