Three researchers who have been examining the reasons for the shortage of secondary science teachers from ethnic minorities said that training institutions with financial worries were more loath to admit students who might need language support in both college and school.
Marilyn Leask, of De Montford University, Bedford, and Sheila Turner and Tony Turner of the Institute of Education, London University, said that some schools which had joined colleges in a school-based partnership scheme were willing to support the development of such candidates.
But they added: "Other schools, conscious of their need to maintain high academic standards, were reluctant to take on student teachers who might need extra support."
Ethnic-minority applicants who had experienced only didactic teaching methods were also at a disadvantage because PGCE selectors sometimes doubted whether they could adjust to a more pupil-centred model of teaching.
Many unsuccessful candidates are, however, no longer being told why their applications have been rejected.
"The increasing openness of selection procedures and the use of selection criteria, under pressures from equal opportunity policies within institutions have paradoxically come into tension with the growing confidence of candidates to ask tutors to reveal their reasons for decisions and to challenge perceived racism," the researchers said.
Only one of the six university education departments that they surveyed had any PGCE tutors who were themselves from ethnic-minority groups and though most of the institutions had a policy of positive discrimination only two of them targeted recruitment advertising at ethnic-minority newspapers.
The researchers also said that no clearly defined criteria were being used to select graduates for interview, a deficiency that the Graduate Teachers' Training Registry could help to remedy.
In 1992, 51 per cent of black applicants for PGCE chemistry courses were rejected, compared with 30 per cent of Asians and 21 per cent of whites. The corresponding figures for physics were 33, 45 and 23, and for biology, 46, 41 and 24.
Recruitment to initial teacher education: issues of selection, by M Leask, S Turner and T Turner, the STEM Project, Science and Technology Group, Institute of Education, University of London, Bedford Way, London WC1H OAL.