By Nick Assinder
Political correspondent, BBC News website
Tony Blair once asked his welfare minister to think the unthinkable - then quickly asked him to forget what he had thought.
Jobless will be forced to do community work
And for decades, both Labour and the Tories have talked about radical welfare reform, often looking to the US and so-called workfare schemes.
Both sides, however, have always stopped short of going all the way down that no-work-no-benefits-style approach. Until now.
Now there is some sort of cross party consensus that the only way to tackle the massive social security budget and tackle fraud is to reduce the size of the welfare carrot and increase the size of the stick.
The government has proposed a series of measures aimed at "helping" (for which opponents read "forcing") more and more people - single parents, for example - back into work and off schemes such as incapacity benefit.
Most recently, the prime minister announced proposals to see anyone refusing to undergo training losing their long term benefits.
But it is David Cameron who is now attempting to win the crown as the most radical welfare reformer for decades - and he is going very much further down the workfare road than any previous political leader, with his "work for welfare" green paper.
His plans draw heavily on the American experience and come after shadow minister Chris Grayling visited New York to view the workfare scheme there, which see the jobless forced to undertake community work such as street cleaning.
Mr Cameron has opened real divide with Labour
Under the proposals, a Tory government would set a new, two-year limit for jobless welfare claimants, after which time they would have to join a mandatory, year-long community work programme - cleaning streets and public buildings of graffiti and chewing gum for example - or face losing their payments.
The two year period would be cumulative, not just continuous periods out of work, in an attempt to stop people signing off for short periods only to go back on benefits.
New, privately-run, "back-to-work" centres would also be created around the country to offer the jobless help in finding work and making job applications.
They would be expected to spend most of the working week at the centres.
After two years, if they were still jobless and refused community work, they would lose their benefits.
According to Mr Grayling, the scheme would put people "closer to work" and, over the life of a parliament, might save £3 billion. He believes some 200,000 job seekers allowance claimants have been on the benefit for more than two years.
He confirmed the money saved would first have to be paid to the private firms running the new centres before then being used, as previously promised, to cut the tax burden on married couples.
Ministers have dismissed the scheme as hugely expensive and claimed only their plans for training would successfully help people back into work.
And it has been pointed out that US schemes, in New York and Wisconsin for example, have not cut the welfare budget because any cash saved has been paid out to the private firms running the centres.
But these proposals have opened up a real divide between the Tories and Labour over one of the biggest political issues which is certain to be a major election battleground.