The race storm was further fuelled by Michael Powell, the chief executive of the Council of Heads of Medical Schools (CHMS), who tried to explain the figures by saying that black students "matured late" or failed to have the right personal characteristics to succeed.

The Manufacturing, Science and Finance Union, which represents 65,000 health service workers, described his statement as "bizarre".

National Secretary Roger Kline said: "It is unbelievable that such discrimination was still taking place after the determined efforts by health ministers to tackle racism."

He has written to Health Secretary Frank Dobson and Education Secretary David Blunkett asking for an inquiry.

The CHMS has announced that sixth formers will be allowed to apply to only four rather than five medical schools in future, in a bid to reduce bias against ethnic minority applicants.

It is thought that reducing the overall number of applications that the schools must process will allow more time to reflect on each

This, it is hoped, will reduce the chance of a snap decision based on an applicant's name or background.

The current university admission system allows students to apply to five different medical schools.

The policy change, limiting this to four, was agreed between university admissions officials and the CHMS. It follows evidence that students from ethnic minorities were less likely to gain places on medical courses.

Only 15% success

Last year, only 15% of ethnic minority applicants won places in medical schools, compared to 55% of whites.

Would-be medical students will have less choice

Michael Powell, executive officer of the CHMS, said: "Medical schools get 60,000 applications from 12,000 applicants for 5,000 places.

"With this many applications, it is very difficult to give every candidate the consideration they deserve."

"We can't tell from the data we have whether there is any direct bias at all, although there is statistical evidence that applicants from the ethnic minorities are disadvantaged."

'No bias during interviews'

He said that whatever bias might occur was most likely to happen during the initial sifting of applications.

The Commission for Racial Equality was supportive of the plan.

A spokesman said: "Now there is an action plan, all we are really concentrating on is to make sure it is implemented."

A statement from the British Medical Association earlier this year claimed that the NHS was "institutionally racist".

And research by East London GP Dr Sam Everington revealed that applicants to medical schools with "European sounding" names were far more likely to be offered places than those with those with names sounding less European.