But his means of paying for the £5.5 billion plan, through a combination of a bank bonus tax and a squeeze on the pension pots of the better off, came under attack with the Tories accusing Labour of recommitting funds over and over again and the Institute of Directors decrying the "bashing" of high earners.
Under Labour's scheme, under-25s on Jobseeker's Allowance for more than a year - two years for others - would have to take a taxpayer-subsidised job for six months or risk losing their benefits.
Firms and voluntary sector groups would provide 25 hours' employment a week over six months at the national minimum wage with the UK Government paying wages and employers' National Insurance.
Last month, it confirmed reports that funding - which includes taking the proceeds of restricting pension tax relief for high earners - was only in place for 2015/16.
But now it has made clear the scheme will be affordable right through to 2020.
Mr Miliband said: "We can't have a recovery that's just for a few banks. We've got 56,000 young people who have been unemployed for over 12 months. A Labour government will tax the bankers' bonuses and put our young people back to work."
But Sajid Javid, the Treasury Minister, said: "Labour's sums don't add up. They are proposing yet more unfunded spending, meaning more borrowing and more taxes to pay for it. And Labour's bank tax is a short-term political gimmick that they want to spend ten times over."