Teachers in Bristol, and the London boroughs of Tower Hamlets and Waltham Forest, are threatening to strike if the staff lose their jobs.
The NUT says some schools are planning to replace specialist teachers with books, musical instruments or classroom assistants, when the new ethnic-minority achievement grant is introduced in September.
Doug McAvoy, NUT general secretary, said that after the Macpherson report on the murdered teenager Stephen Lawrence, local authorities should realise "that the last thing they should be doing is making ethnic-minority teachers redundant".
Mr McAvoy said that although most councils have managed to avoid job cuts, at least eight councils - Bristol, Kent and the London boroughs of Enfield, Harrow, Tower Hamlets, Waltham Forest, Hammersmith and Fulham, Merton and Enfield - were proposing to issue notices warning of possible redundancy.
The union says hundreds of staff could be affected.They were previously employed using Section 11 funds for language support for minority pupils. Last November ministers announced plans to replace Section 11 with the pound;15 million grant. Schools can decide how they want to use the cash, which it is hoped will boost poor achievement in the inner cities. The union says several schools have already decided not to re-employ teachers.
Bristol staff who have kept their jobs face a salary freeze for three years and may lose responsibility points. The NUT in Bristol plans to take a claim of race discrimination to a tribunal.
Mr McAvoy said: "The advice to LEAs from both ministers and their own legal teams was that waving around redundancy notices was unnecessary and would bring trouble."
In Waltham Forest, Connaught school for girls plans to cut teaching posts and use the cash to fund, among other things, a black history club, a steel band and Asian musical instruments. "I'm not saying these things aren't worthy, but surely the teachers have to be the primary resource," said Ron Haycock of the Waltham Forest Teachers' Association.
In Waltham Forest schools got a percentage of the cash based on numbers of minority pupils. The council plans to retain 10 per cent of their pound;2.9 million grant, to pay for training and advisers. "That's pound;290,000. How many salaries is that?" asked Mr Haycock.
A spokesman for the Department for Education and Employment said ministers were monitoring how many but that it was "right schools made the key decisions".