There are not enough poor or black students at the UK's two top universities, Mr Jackson has told students.

The civil rights campaigner said he was concerned about the situation at Cambridge and Oxford.

He said most of the world was not white or Christian and was poor, and urged Oxbridge students to "learn how to participate".

Mr Jackson made his remarks to student reporters in Cambridge before delivering a speech at the university.

"I am concerned," he said. "At this university and at Oxford there are too few students who are poor and who are black.

"You must learn how to participate in the world. Most folks are yellow, brown, black, non-Christian, poor and they don't speak English."

Mr Jackson said educational achievement could be measured by grades, but insisted background was also important, adding: "Some flowers bloom and blossom late."

He later gave more detail of his concerns in his speech to Cambridge's debating forum, the Cambridge Union Society.

"Even in 2013, very few black students from Britain are accepted and attend Oxbridge colleges," he said.

"Twenty-one Oxbridge colleges took no black students last year. In 2009, of Oxford's 2,653 new undergraduates, just six 'black Caribbean' candidates from the UK - out of 35 who applied - were accepted for study at Oxford.

"More than 20 Oxbridge colleges made no offers to black candidates for undergraduate courses last year and one Oxford college has not admitted a single black student in five years.

"And it is still the graduates from these elite universities that go on to become PMs, MPs and business leaders, that propel these race gaps in education into the political and economic arenas."

He added: "We live in a different world today that will reject these disparities. There is a growing insult level among the locked out and the rejected. These gaps create tensions that lead to wars and, unfortunately, sometimes to terrorism."

Mr Jackson said everybody grew when walls came down and told students to "dream big".

"How should people and nations adapt and adjust? With acceptance and inclusion, where we all become more secure and better off," he said.

"Not by pushing off and away, reconstructing barriers of exclusion, blaming immigrants for the global and European economic and job crisis - or seeking to ban immigration to Britain and inflaming racial, religious and ethnic tensions."

He added: "Your generation now relate to Britain's new immigrants as neighbours, classmates, business partners, MPs and voting partners.

"As their population grows, so too will their voting and political power, and their demand for equality and a level playing field.

"So forging a new UK - one that is inclusive and sets a level playing field for all of its people - brings forth new challenges and opportunities.

"As the UK and Europe seek to re-emerge and restore their economies shattered by the global banking crisis, it should not be at the expense of Britain's black and ethnic minority or immigrant population."