A pound;100 MILLION legal battle pitting minority teachers against New York City education chiefs is threatening President Bush’s key reform.

More than 3,300 black and Hispanic teachers are suing New York education department for making them sit “culturally-biased” general knowledge tests.

The test - which must be passed to gain certified teacher status in the city - has seen many black and Hispanic teachers expelled from the profession, even if they have taught for years. Only 56 per cent of blacks and half of Hispanics passed Last, the “liberal arts and sciences test“compared with 93 per cent of whites.

Experienced teachers who failed have been demoted to auxiliary status, with the loss of protected employment, lower pay and an inferior pension scheme.

If the teachers win their case, other states may come under pressure to water down their tests.

Any relaxation of the rules would be a blow for teacher testing, a cornerstone of Bush’s education reforms. His administration has vowed that by September 2005 every state pupil must be assigned a “highly qualified” teacher.

In New York, Last is one of a battery of tests that instructors must pass.

If they fail, they may retake but must start again at the bottom rung of the career ladder.

Barbara Olshansky, the lawyer representing teachers seeking reimbursement for lost pay, disparaged Last as a “test of fluency in the dominant culture”, that discriminates against minorities.

Ms Olshansky added that more than 70 per cent of New York pupils were black or Hispanic compared with just 35 per cent of teachers.

However, the Education Trust, which campaigns on behalf of minority students, sees the tests, as a way to ensure underprivileged children get good teachers.