And any under-21s failing to get a job within a year will be forced to carry out 12 months of community work in a bid to end a "street corner benefit culture".

The moves are part of benefit plans being unveiled this week by shadow work and pensions secretary Chris Grayling who said Government proposals were too lax.

"In Britain today, where jobs a plenty have been created, there is no excuse whatsoever for a young, able-bodied person to be outside the labour force.

"But we all know that on a typical working day you can see young people hanging around in town centres in almost every part of this country," he said.

One young man he met in Manchester wanted to find a job after being in trouble but "no-one was taking him by the scruff of the neck and steering him in the right direction", said Mr Grayling.

"So he was hanging around on benefits. This has to stop."

Mr Grayling said that under Government plans, young people would wait a year before getting a place on "any kind of substantial return to work programme" and then faced another six-month wait if they found a job but lost it again.

The Tories would also stop people "playing the system" by signing off benefits just before the deadline for the New Deal and then signing back on shortly afterwards to restart the process.

Mr Grayling is due to give more details of his planned welfare shake-up in a speech to the Centre for Policy Studies in London.