The National Union of Teachers gave Cuckmere House school, Seaford, Pounds 4,000 towards its bid to become a specialist special needs college, it has been revealed.
Such a move would have been unthinkable five years ago when the union opposed the Government's plans for more specialist schools to bring an end to the "bog standard" comprehensive.
"An expansion of specialist schools will create a divided system," Doug McAvoy, the then NUT general secretary, said in 2001. But since then ministers have said all secondaries can become specialist and the union's attitude has mellowed.
John Bangs, the NUT's head of education, said the union had decided to sponsor the East Sussex school, which caters for around 50 pupils with severe emotional and behavioural difficulties, because it wanted to research the impact that SEN specialist status could have in the wider community.
Cuckmere House needed to find a total of pound;20,000 for last year's successful bid for specialist status.