Large firms will have to train up a British apprentice for every overseas worker they bring to the UK under plans announced by Labour.
Ed Miliband said the policy could result in the creation of 125,000 new apprentices over five years because the long-term solution for the UK economy was to develop a highly skilled homegrown workforce.
As part of efforts to prevent the exploitation of workers he also promised a huge increase in the fine for employers who failed to pay the national minimum wage, with the penalty set to rise from £5,000 to £50,000 under a Labour administration.
Signalling a tougher stance on immigration, Mr Miliband told the Sunday Mirror the party was "changing under my leadership" and had "learned lessons from the past".
He said: "I want a high wage British economy, not a low wage brutish economy.
"We've got plans to make that happen, to drive up skills. So we are going to say to any firm that wants to bring in a foreign worker that they also have to train up someone who is a local worker, training up the next generation.
"We think that can create up to 125,000 new apprenticeships over the course of five years and that is a massive boost for skills for our young people."
The tenfold increase in fines for the minimum wage would "stop the exploitation which undercuts workers that are already here".
He said: "At the moment the maximum fine is £5,000. If you do flytipping the maximum fine is £50,000.
"So we are going to say: maximum fine £50,000 for employers who systematically abuse the minimum wage. We are going to take action in the care sector where up to 220,0000 are not being paid the minimum wage, that's a third of the workforce."
He added: "We are going to stop that exploitation, we are going to drive up skills and that's the way to make our economy work for working people in Britain."
Mr Miliband said around 50,000 people were brought over from abroad who had some skills.
"We are saying we shouldn't stop people bringing people over from abroad if they have something particular to contribute, and there would have to be criteria for that, but also you've got to show your responsibility as an employer to train the next generation," he said.
"I think that's fair, I think that's right and also it shows that the long-term solution for our economy is about training our own workforce."
The Labour leader said his party would not "cut ourselves off from the world" but would set rules to stop workers being exploited in a "race to the bottom".
He said: "I think immigration can benefit our country. I think we should welcome those who want to work and make a contribution.
"But it's got to be done in the right way, that's what we are about."
The Labour Party conference, which gets under way tomorrow in Brighton, is set to focus on helping families cope with the rising cost of living.
Lucrative industries could be forced to pay staff more under plans to "strengthen" the minimum wage and there would be guaranteed 8am-6pm childcare for primary pupils.
The Opposition is also pledging to reverse the Government's controversial cut in housing benefit - dubbed the "bedroom tax" by critics.
Up to one million workers could benefit from plans to raise the minimum wage to make it better reflect the true increase in the cost of living.
"Abolishing the bedroom tax. Strengthening the national minimum wage. Childcare there for parents who need it," Mr Miliband told voters in the centre of Brighton as he took his message to the streets.
"That's what I mean by tackling the cost of living crisis at this conference. That's what I mean by a government that fights for you."
In contrast, David Cameron's Government would stand up only for the "privileged few", he told them.
"This next election is going to come down to the oldest questions in politics: whose side are you on and who will you fight for?"
The minimum wage was worth £20 less a week after inflation then when the Tory/Lib Dem coalition came to power, he said.
Mr Miliband has appointed Alan Buckle, deputy chairman at accountants KPMG, to investigate how the role and powers of the Low Pay Commission could be extended to strengthen the minimum wage.
Labour said that if the national minimum wage (NMW) had risen in line with the cost of living it would be 45p an hour higher than the current level, which is due to rise next month from £6.19 to £6.31.
He will also investigate whether different sectors, such as finance, IT or construction, could afford to pay a higher rate to their staff.
The focus on eyecatching policy announcements came as a drip-feed of claims from Gordon Brown's former spin doctor, Damian McBride, threatened to cast a shadow over the conference.
Mr Miliband told The Observer that Mr McBride will never work again for Labour while he is leader and that anyone found briefing against a colleague will be sacked.
"It is totally unacceptable," he said.
The Labour leader told The Observer he complained about Mr McBride's behaviour to Mr Brown.
"I complained to Gordon about what Damian was up to," he said. "I was worried by him and I said to Gordon I was worried by him."
In further measures to boost apprenticeships, Labour will accept key recommendations from a report by Professor Chris Husbands, director of the Institute of Education.
The party would e nsure apprenticeships in Britain are "gold standard" and give groups of employers more control over skills funding and standards in return for them driving up the number of places available.
The party claims its plans, together with an existing commitment requiring large firms to offer apprenticeships as a condition of receiving government contracts, will double the number of "gold standard" schemes from 190,000 to 400,000 over the next parliament.
Former deputy prime minister Lord Prescott used his Sunday Mirror column to warn against any attempt to woo the Liberal Democrats ahead of a possible coalition after 2015.
Drawing on his experience of the Lib-Lab pact under James Callaghan, h e said: "It all ended in tears with the Liberals pulling out to their advantage, claiming credit for good and the denial of the rest.
"So I'm against coalitions. People don't get the policies they voted for and end up with a political fix.
"So this conference I don't want to hear about 'reaching out' to Lib Dems."
He added: "Let's shout about the good things we did and can still do, not tell our people to go back to their constituencies and prepare for coalition government."