The Office for Budget Responsibility said the economy would grow in the first quarter, avoiding a technical recession, and revised up its 2012 growth forecast to 0.8pc from a November forecast of 0.7pc.
The OBR's growth projection also left the government's medium-term deficit reduction and fiscal target plans remain intact, in what was a considered a fiscally neutral Budget.
It said the improved forecast for this year reflected its view that "the economy carried a little more momentum into the new year than previously anticipated".
The lack of major revisions was a relief for George Osborne, under pressure to keep fiscal discipline at the forefront of the Budget following the decision by Moody's and Fitch to put the UK's treasured AAA rating on negative outlook over recent weeks.
Fitch said the Budget and latest OBR forecasts were "neutral" for its AAA status, but warned the UK remained "vulnerable to adverse shocks".