Young people out of work for a long time should be guaranteed a job but stripped of their benefits if they reject the chance, Ed Miliband has said.
The Labour leader said he would introduce the idea if he became Prime Minister.
He pledged that all under-25s who are jobless for more than a year will be given paid work for six months, with the plan funded by a tax on bank bonuses.
Under his policy, the Government would pay businesses enough money to cover 25 hours of work a week at minimum wage - approximately £4,000 per person. In return, the employers must offer 10 hours training a week.
If the unemployed individual turned down the work or was sacked from the job, sanctions would include a temporary withdrawal of benefits.
In a speech, Mr Miliband described his promise as a "real jobs guarantee" and added: "Saying 'no' is not an option."
He criticised the coalition for not doing enough to stem rising unemployment.
"What is their solution? A Work Programme which does not guarantee work. A jobs programme scheme from this Government which does not offer jobs," he said.
"Work experience of course has a role to play in helping people into work. But work experience is not the same as a real job. It cannot be the summit of our ambitions.
"There is only one solution to a jobs crisis - jobs."
Conservative co-chairman Baroness Warsi accused Labour of "squandering" millions last time they offered guaranteed jobs.
"Now they want to repeat this failed experiment, but they've already spent the money they say they'd use to pay for it 10 times over," she said.
"This government is committed to getting our country back on track.
"Labour must stop these irresponsible calls for more spending, more borrowing and more debt in the middle of a debt crisis," she added.