George Osborne said the independent Office of Budget Responsibility had revised the 2011 growth rate down to 1.7 per cent from 2.5 per cent previously, after snowy weather in winter hit the service sector.
Government borrowing is also falling more slowly than hoped and will be £146bn this year, falling to £142bn next year, and will still be £29bn in the final year of deficit reduction in 2015/16.
The OBR expects 2012 growth to be 2.5 per cent, rising to 2.9 per cent in 2013 and 2014 and falling slightly to 2.8 per cent in 2015.
UK national debt as a share of national income will be 60 per cent this year, before peaking at 71 per cent and falling marginally to 69 per cent by the end of the period.
Labour leader Ed Miliband hit back at the forecasts, saying Osborne repeatedly promised growth but delivered the opposite.
“One fact says it all and he couldn't bring himself to say it: Growth down last year, this year and next year,” he said.