He was speaking to a conference of colleges and private training providers last week about the Government's Entry to Employment - E2E - programme, due to be launched in August.
E2E aims to reduce the number of so-called "neets," what the Department for Education and Skills calls 16 to 19-year-olds who are not in employment, education or training. The aim is cut the number by 10 per cent by next year.
This would be the first step towards ensuring 90 per cent of the age group are in education, training or employment by 2010. Eleven E2E pilot areas are in operation.
There is a pound;164m budget but, such is the urgency of E2E recruitment, that providers have been told to enrol every young person in sight.
The Learning and Skills Council has given a funding guarantee to its local councils and would raid other budgets if providers exceeded their target numbers. But ministers, still haunted by the failure of the individual learning accounts scheme, are equally concerned to make sure quality is maintained.
Mr Lewis said: "These young people will be badly let down and alienated if you do not get this programme right.
"We want genuine provider and LSC partnerships on the ground to make it work, not just ticking boxes and attending meetings in pursuit of government money. We have to convince these youngsters we are genuinely sensitive to their needs and want them to achieve."
He said the DfES's 14-19 and post-16 education and training policies, as well as the credibility of the LSC, depend on its success. He said E2E was not just another initiative in "other further education", but "an integral part of the nation's economic success."
He announced that childcare services would be extended to all young people on work-based learning programmes from August to help recruit this "challenging" target group.
Ian Ferguson, a key member of the LSC's young people's learning committee, said employers and colleges should not be content to recruit just 90 per cent of the "neets" in their area. He said: "Every young person has an entitlement to learning. If you have a valid programme you'll get funded, even though you may have to fight for it."
Martin Lamb, assistant director of policy and development at LSC headquarters in Coventry, said he was keen to show the E2E programme could be up and running in one year. The launch will happen even before the 11 pathfinders have even been evaluated.
He said: "E2E is a high priority because of the statutory entitlement and national targets. We will go back to the DfES for more funding, if necessary. But the bids must be reasonable and evidence-based and not pie in the sky. This is not a time-serving programme or just a rehash of pre-16 work with special needs"