Black workers earn much less than similarly qualified white workers, at all levels of education, with an average pay gap of 23%, according to research.
The figures, from the Trades Union Congress (TUC), come as education chiefs were on Monday summoned to Downing Street by David Cameron as part of an anti-discrimination drive. They are due to meet with business secretary Sajid Javid to discuss why young black men are more likely to be in prison than studying at a top university.
As part of Cameron's plans, universities will be required to disclose what proportion of ethnic minority applicants get places. He has also warned police, the courts and the armed forces that they were all the focus of his plan to tackle social inequality, suggesting it might be fuelled by "ingrained, institutional and insidious" racism.
Labour MP David Lammy has also been recruited by Number 10 to carry out a major review into discrimination in the criminal justice system, including why black offenders are more likely to be jailed for the same offences as their white criminal counterpart.
According to TUC figures quoted by the BBC, black graduates earn on average £14.33 an hour, compared with £18.63 earned by white graduates.
The average pay gap between black and white workers with A-levels is 14%, the TUC says. At GCSE level it is 11%.
The TUC's general secretary Frances O'Grady said race "still plays a huge role in determining pay" and the "harsh reality" is that black and Asian workers are getting paid less than their white counterparts.
O'Grady told the BBC that the government "cannot afford" to ignore the TUC figures, and "must now take genuine action to tackle pay discrimination".
The Runnymede Trust, a leading race equality think tank, has previously found that pay gaps are not due to the type of university attended, as they even extend to black workers with degrees from the most selective Russell Group of universities.
TUC's analysis, of Labour Force Survey figures from 2014 and 2015, shows the pay gaps are widest for those with higher qualifications.
"This suggests that education alone will do little to address racial inequalities, and the need for interventions that directly challenge racial inequalities in the workplace," it said.
The TUC is calling on the government to recognise the scale of the problem and to urgently develop a race equality strategy.
The Prime Minister said on Sunday that the transparency rules should prompt institutions such as Oxford to work harder to broaden their intake, something it said Monday that it does "not see the need" for.
Cameron said the absence of any black generals, the fact that just 4% of FTSE 100 chief executives were from ethnic minorities and that young black men were more likely to be in prison than at a top university "should shame our country and jolt us to action".
"I don't care whether it's overt, unconscious or institutional – we've got to stamp it out."
Javid said it was "striking" that the 2,500-strong 2014 intake at his own university - Oxford - included only 27 black students and suggested it was "not doing enough to attract talent from across our country".
Oxford said it did "not see the need" for such legislation and insisted the effects of social inequality were "already pronounced before children begin formal schooling" and could not be addressed by higher education alone.
"Any serious solution to the problem of unequal educational progression must take into account the unequal distribution of high attainment across schools, socio-economic groups, even geography," a spokesman said.
He said 367 undergraduates from ethnic minority backgrounds were accepted in 2015, 15% more than in 2010 - 64 of those being black students, up from 39 five years ago.
"We are constantly working to update what information we provide and although we do not see the need for further legislation, we would welcome discussions on what more information we could publish," the spokesman said.
Wendy Piatt, director general of the Russell Group of elite universities, said universities invested a "huge amount of time, effort and resources" into broadening the student mix but needed more help from others.
"There are still far too many children from disadvantaged backgrounds underachieving at school and receiving poor advice and guidance.
"It will take time, commitment, and sustained action from a range of agencies to raise pupils' aspirations, increase attainment and improve the advice and guidance offered."
Sir Anthony Seldon, University of Buckingham vice-chancellor, welcomed the push by Cameron, one of several prime ministers of whom the historian has written biographies.
"It is deeply wrong that black and other ethnic minority students are so poorly represented in our universities, notably those like Oxford, which should be leading the way," he said.
Lammy, a qualified barrister, has been tasked with finding solutions to what the PM called a "disgraceful" gulf in sentencing treatment.
He is due to produce recommendations on how to tackle discrimination at all stages - from arrest, through courts and prisons to rehabilitation - by the spring of 2017.
Official figures show 61% of black and ethnic minority offenders in England and Wales receive custodial sentences, compared with 56% of their white counterparts.
They also make up a disproportionate amount of Crown Court defendants (24%).
Lammy told the Murnaghan programme on Sky News that he had discussed the appointment with Labour leader Jeremy Corbyn, who he said had "taken up these issues within the criminal justice system for many, many years".
"There are occasions when the issue is beyond party politics. This is absolutely one of them," he said.
Shadow justice secretary Lord Falconer welcomed the review but said ministers must ensure it prompted "real change".