British Chancellor George Osborne describes Labour and the unions as "the forces of stagnation" - claiming they are holding back economic recovery.
At the World Economic Forum in Davos, Mr Osborne vowed to reshape the British economy and to be "bold" promoting economic growth.
But he accused the unions and Labour of standing in the way of efforts to get the economy moving again.
Unions have refused to rule out co-ordinated strike action over cuts to public sector pensions.
The BBC reports the government has stressed that it wants to continue talking to the unions - but has not ruled out new laws banning co-ordinated strike action as a "last resort".
Mr Osborne rejected union calls to change course following this week's "disappointing" growth figures.
"If we did that, we would be plunged back into where we were a few months ago with people raising very serious questions about Britain's ability to pay its way in the world, and that will provide no platform for growth going forward," he said.
Mr Osborne said he was "acutely aware" that families were feeling the squeeze over rising prices.
He said the UK economy had to be rebuilt with less emphasis on financial services and more on business investment and exports - and he claimed there were signs this was starting to happen.
"We have got to be as bold in promoting growth and removing barriers to business expansion, and fighting the forces of stagnation, as we have been in dealing with the deficit," he said.
Govt being held back
But he said governments were being held back by people who oppose efforts to "create more competitive markets".
He said the trade unions and opposition had opposed changes to employment tribunals and were opposed to other "difficult" decisions aimed at promoting growth.
"I regard these people as the forces of stagnation, when we are trying to get the British economy competitive again, moving forward again."
Prime Minister David Cameron earlier vowed to "see through" the government's plan for deep spending cuts despite fears of their impact on economic growth.
He said cutting the deficit would be "tough" but the economy would "bounce back" if Britain stuck to its course.