The president laid out $4 trillion in cuts to the deficit over the next decade as he seeks to reassure the large number of swing voters and conservative Democrats that he is serious about reining in government spending – a primary source of attack by Republican presidential contenders.

But, in a speech in Virginia in support of the proposals on Monday, Obama said a fresh wave of cuts should be delayed until the economy is in better shape to absorb them. In the meantime he proposes new investment in education, jobs and infrastructure, in part paid for by cuts to military spending with the end of the war in Iraq.

"The main idea in the budget is this: at a time when our economy is growing and creating jobs at a faster clip, we've got to do everything in our power to keep this recovery on track. Part of our job is to bring down our deficit and if Congress adopts this budget then along with the cuts we've already made then we'll be able to reduce out deficit by $4 trillion by the year 2022," he said. "By reducing our deficit in the long term, what that allows us to do is to invest in the things that will help grow our economy right now. We can't cut back on those things that are important for us to grow. We can't just cut our way in to growth."

The president zeroed in on tax rates for the wealthy – an issue pushed to the fore by the revelation that the frontrunner for the Republican nomination, Mitt Romney, pays taxes on his $220 million fortune at a rate around half of that of most Americans.

Obama said that the wealthiest 2% of Americans are scheduled to get a $1 trillion tax break because of what was supposed to be a temporary reduction in rates passed during George Bush's presidency which has already cost another $1 trillion in revenues.