Ballots on industrial action are expected over plans for Fresh Starts at Marina high, Brighton, and Hatcham Wood in Lewisham, south London, because of fears of teacher redundancies.
The NUT has approved a ballot of teachers in Brighton and Hove, following an informal poll in which 95 per cent voted in favour of a series of one or two-day strikes. Almost 60 per cent of the council's 810 teachers took part.
Results of a similar informal poll in Lewisham over plans to make five teachers at Hatcham Wood redundant will not be known until next week.
David Blunkett, the Education and Employment Secretary, has so far only agreed that seven failing schools be given a Fresh Start. Under the scheme the schools are closed and then re-opened with a new name, and more controversially, with new teachers.
In Brighton, the NUT is threatening action because the future of between 15 and 20 teachers at the former Stanley Deason school, now Marina high, has yet to be determined. Of the staff, around 20 have been given jobs at the new school and a small number have agreed to redundancy or early retirement.
According to Dick Boland, NUT regional secretary, teachers will be asked to vote for "sustained discontinuous strike action to prevent redundancies".
The new school to open in Lewisham - to be called Telegraph Hill - has so far recruited 14 teachers from the 41 staff at the former Hatcham Wood. Five teachers have not been offered posts or agreed severance terms. Almost three-quarters of the jobs in the new schools were advertised. The NUT is proposing a one-day strike.
Lewisham Council is planning a revised curriculum in Telegraph Hill school to be based on modular courses. The intention is give students greater choice.
The two schools that have already had a Fresh Start have re-opened with a substantial proportion of new teachers.
Fourteen teachers from the former Earl Marshall school in Sheffield were sacked and only 19 transferred to the new secondary. At Blakelaw in Newcastle, only 13 teachers joined the 30 staff recruited for the new school.
Ministers want all schools that have been on the failing list for more than two years to be considered for Fresh Start. Schools in Nottingham City and Hull are currently waiting for approval. There are more than 500 failing schools, of which about 90 are secondaries.