Social mobility is a litmus test of a government's achievements
The government is to outline proposals aimed at increasing social mobility in the UK, amid opposition claims that progress in the area has stalled.
Cabinet Office Minister Liam Byrne is expected to say teachers will get £10,000 in loyalty payments to work in England's toughest schools.
Gordon Brown has said more must be done to improve people's life chances, describing it as a "national crusade".
But the Conservatives say Labour has not addressed inequality properly.
The government proposals are likely to focus on ways of breaking down barriers to social advancement in secondary and higher education, business and professions such as law and medicine.
A White Paper is set to include help for schools in economically deprived areas, including financial incentives to help recruit and retain the best teachers.
Mr Byrne told BBC Radio 4's Today programme: "This is something we feel very strongly about...
"We cannot improve social mobility with just a one-part policy. We have got to invest at every stage of life."
Former health secretary Alan Milburn has been asked to head a commission looking at ways of widening access for people from disadvantaged backgrounds to the civil service, media and higher roles in the armed services.
Labour acknowledges progress has been slower than it would have wished since 1997 but says it remains committed to reducing economic and social disparities.
Speaking on Monday, Mr Milburn said the government had "raised the glass ceiling but we haven't broken through it".
A report published by Downing Street in November suggested that social mobility had neither improved nor worsened between 1970 and 2000 but that some advances had been made since then.
However, a report produced by a Lib Dem think tank this week said a child's success in life was still largely determined by its parents' income and social background.
The Social Mobility Commission argued education had not proved "the great leveller" that had been hoped.
It proposed financial action, such as interest-free loans and tax credits, to help open educational opportunities to low-income families, as well as a review of schools' admission policies.
The Conservatives argue that the UK is now one of the most socially entrenched societies in the world and that Labour has made little or no difference over the past decade.
In its own report published last month, the party called for early intervention to break the cycle of what it said was family breakdown, educational underachievement and unemployment in areas of the country.
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Pledges included increased funding for health visitors and apprenticeships and greater focus on subjects like maths and foreign languages.
Shadow skills secretary David Willetts told Today the UK had a "shockingly bad performance" on social mobility and needed to tackle it "at every stage as children go through school and university".
He said: "The careers service which used to be so important has been dismantled under this government and we are committed to putting it back together, so that every child gets objective advice at school about how they can achieve their ambitions.
"The government talks a lot about the problem of low aspirations, and that's part of the problem. But another part of the problem is that a lot of these youngsters have absolutely understandable aspirations to get a decent job, but they are not given the route to get there.
"They are not given the advice about how to get from where they are to what they want to achieve, and then they become demoralised."