Ed Miliband has accused the Government of taking backward steps on social mobility by allowing inequality to grow and denying bright youngsters from poor backgrounds the chance to succeed.
The Labour leader called for action to open up the "closed circles" in elite professions and make it easier for disadvantaged children to go to university.
But he also attacked the "snobbery" that suggests only an academic education is worthwhile, insisting that the UK must give more respect and value to vocational learning and apprenticeships.
Mr Miliband called for a "new bargain with employers", with Government offering the right support and incentives for them to deliver good training for long-term high-value jobs.
And he denounced the Beecroft Report, currently being considered by ministers, which proposes instead reforms of labour laws to make it easier for employers to hire and fire workers.
"The countries that succeed in having a higher-skilled, higher-paid workforce are those where employers and employees show commitment to each other," said Mr Miliband.
"This is the opposite to what this Government wants to do - now considering a proposal from the Beecroft Report to make this short-term culture worse by allowing employees to be fired at will.
"We need an economy based on long-termism, investment, and training.
"Not the short-term, fast buck, take-what-you-can culture that caused the financial crisis in the first place."