Labour's promise to introduce measures to get the long-term unemployed and under-25s into work would last throughout the next Parliament, the party said.
Ed Miliband's party will promise to fund the package via a tax on bankers' bonuses and high-earners' pensions in its 2015 manifesto.
Last month the party confirmed reports that funding - also including the proceeds of restricting pension tax relief for high earners - was only in place for 2015/16.
Now it says the scheme - estimated on present claimant levels to cost £1.9 billion in its first year and £900 million a year thereafter - is affordable right through to 2020.
Under the 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 benefits.
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Nearly 38,000 runners will hope to complete Sunday's London Marathon making it the biggest event in its 35-year history.
Rain across central Britain with longer, intense downpours with thunder in places this evening. A lucky few will stay sunny and dry.
Planning on going to the London Marathon tomorrow? Read our handy guide first!