The Government's flagship universal credit is late and £100m over budget, Labour claimed on Monday.
Work and Pensions Secretary Iain Duncan Smith believes consolidating all benefits into a single payment will simplify the welfare system.
But shadow work and pensions secretary Liam Byrne on Monday said the single credit was nine months late and its costs were rocketing.
Byrne said: "In the House (of Commons), Iain Duncan Smith says universal credit is on time and on budget.
"Yet his ministers say it's £100m over budget and his staff newsletter says it's nine months late.
"The tragedy is that to pay for this crumbling revolution, the Government is reducing the welfare state to a money for nothing deal for working people."
In a speech to the Social Market Foundation to mark the 70th anniversary of the Beveridge Report which was the basis of the welfare state, Byrne said the universal credit was "disappearing over the horizon".
He added: "What happened to the revolution? It has failed; rising welfare bills, rising unemployment, falling living standards.
"I don't know anyone who would say that's a success.
"It's no surprise the revolution is in trouble when the revolutionaries in charge couldn't organise the lightest of refreshments in a brewery."
Duncan Smith said: "The rollout of universal credit will begin on time in October 2013, as we have always said, and in fact it will begin early in Manchester and Cheshire from April of next year.
"Liam Byrne is well aware of these facts.
"There is no doubt about the need for radical welfare reform and our commitment to universal credit and making work pay is unwavering."