LONDON The Trades Union Congress, the country's union umbrella body, said on Saturday it will stage the "biggest and boldest" demonstration in its history next March to protest against the government's spending cuts.
The government announced on Wednesday that it would cut half a million public sector jobs, raise the retirement age and slash welfare spending as part of 80 billion pounds of cuts to address a budget deficit of 11 percent of GDP.
The TUC, which represents 6.5 million workers, said the cuts would have a devastating impact and promised a campaign of political pressure to try to turn voters against the plans.
"The union movement and the country face the sternest test in a generation," TUC General Secretary Brendan Barber will say in a speech to union groups in London.
"Not only is the economy on its knees, not only is the law tilted against us, but we have a government in power that is making spending cuts of a speed, scale and savagery never before seen."
Barber has so far shied away from calling for widespread strike action, saying that the TUC would instead focus on harnessing popular discontent resulting from the deepest public service cuts since 1975 to try to sway ministers.
However, some unions have called for "coordinated" action and suggested looking to the example set by their counterparts in France which has seen violent protests and strikes against government reform measures.
Union-backed protests and rallies have already begun in cities and towns around Britain and these will culminate in a national demonstration in central London on March 26.
"Together let's make that mobilisation the biggest, boldest and best event in our history," Barber will say.
The Conservative-Liberal Democrat coalition, which is banking on the private sector to create new jobs and growth, said tackling the budget deficit was unavoidable and the cuts it had made had been fair on all.
However, an influential think-tank has said the austerity measures would hit the bottom half of earners hardest, and Barber warned the cuts would leave the country "less civilised and less tolerant."
"The impact of this brutal, ideological and cripplingly unfair austerity will be truly devastating," Barber will say.
"The evidence is overwhelming and it is indisputable -- these savage cuts will devastate the poorest, the most disadvantaged and the most vulnerable."
(Editing by Steve Addison)