A Labour MP has been asked by David Cameron to examine why black offenders are more likely to be jailed than white offenders in English and Welsh courts.
Former barrister David Lammy will review the “over-representation” of black and minority ethnic (BAME) defendants in the justice system.
Launching an anti-discrimination drive, Mr Cameron also said universities must say how many BAME students get places.
And he said the police and armed forces must act to ensure equal opportunity.
Downing Street said 61% of BAME defendants found guilty in crown courts were given custodial sentences, compared with 56% of white offenders.
Government data published in 2013 suggested that, in each year from 2008 to 2012, black offenders were more likely to have been jailed than white offenders by courts in England and Wales.
“It’s disgraceful that if you’re black, it seems you’re more likely to be sentenced to custody for a crime than if you’re white,” Mr Cameron said.
“We should investigate why this is and how we can end this possible discrimination.”
Mr Lammy, the MP for Tottenham, said he was pleased to accept Mr Cameron’s invitation to lead the “comprehensive, independent review”, which will report back in spring 2017.
“With over a quarter of the prison population coming from a BAME background, the urgency here is clear,” he added.
Government figures suggest BAME people make up 14% of the population of England and Wales.
Mr Cameron said black people were “more likely to be in a prison cell than studying at a top university”.
Writing in the Sunday Times, he said discrimination 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,” he wrote.
The PM rejected what he called “politically correct, contrived and unfair solutions” like quotas, but said forcing English universities to disclose what proportion of BAME applicants achieved places should prompt them to broaden their intake.
Mr Cameron said it was “striking” that Oxford University’s 2014 intake of more than 2,500 people included only 27 black students.
“I know the reasons are complex, including poor schooling, but I worry that the university I was so proud to attend is not doing enough to attract talent from across our country,” he added.
‘Ingrained and insidious?’
He also noted that there are no black generals in the UK armed forces, and “just 4% of chief executives in the FTSE 100 are from ethnic minorities”.
“What does this say about modern Britain? Are these just the symptoms of class divisions or a lack of equal opportunity? Or is it something worse – something more ingrained, institutional and insidious?”
He said under-representation in the police and armed forces was a “stubborn problem”, and organisations should go the “extra mile” to show they are open to all.
The Russell Group, which represents 24 leading UK universities, said “real progress” had been made in the last five years to increase the number of BAME students.
But director general Wendy Piatt said universities “cannot solve this problem alone”.
“There are still far too many children from disadvantaged backgrounds underachieving at school and receiving poor advice and guidance,” she said.