Ed Miliband will today tell a rally opposed to the Coalition's austerity programme that any government would have had to make some spending cuts.
The Labour leader, already under Conservative fire for attending the TUC's "A Future That Works" protest in Hyde Park in London, will tell tens of thousands of protesters this afternoon: "Of course, there will still be hard choices. I do not promise easy times. But I do promise a different and fairer approach. This Government has shown us self-defeating austerity, by cutting too far and too fast, is not the answer."
Mr Miliband will add: "What did the Government say? They told us austerity would help our economy grow. But our economy has not grown. It has flatlined."
More than 250 coaches will bring protesters to London, while similar rallies will take place in Glasgow and Belfast.
Some union leaders will call for a general strike over the cuts. Bob Crow, the general secretary of the Rail, Maritime and Transport (RMT) union, will say: "The marches are a building block towards the objective of co-ordinated action and a general strike. That is why RMT says, march today, strike tomorrow."
Grant Shapps, the Tory chairman, said: "Ed Miliband will be among friends – supporting his union donors who oppose every single one of our spending cuts. You can't be serious about clearing the deficit when you attend a march that calls for an end to austerity."