A TROUBLED school could be heading for strike action - despite its boss saying progress was being made in discussions.

Vital talks for a federation with Macmillan College were put on hold after staff at the Unity City Academy, in Middlesbrough, refused to accept a contract on the advice of the National Association of Schoolmasters Union of Women Teachers (NASUWT).

Union leaders are threatening strike action because they are unhappy with proposed working conditions the federation would create.

A previous ballot at the Academy was scrapped after union officials were unable to discover how many teachers were entitled to vote, because of high sickness levels.

However, Mike Griffiths, the school's chief executive, said he believed progress had been made on the key issues raised by the NASUWT.

"We have agreed to work together positively to address issues of pupil behaviour.

"We have also made very clear that nothing has been imposed in relation to possible change in working conditions.

"All we have done is put forward proposals covering matters such as lunchtime supervision, involvement in activities such as drama, music and sport, arrangements for covering staff absences and joint working between Unity and Macmillan. Any changes will be entirely voluntary."

Union boss Jerry Bartlett painted a different picture.

The deputy general secretary of the NASUWT said incidents when pupils hurled chairs at teachers were putting their safety at risk.

He said: "In the last fortnight, there have been two very serious incidents where severe injury has been narrowly avoided after pupils had thrown chairs down open balconies, which provide internal access to teaching rooms in a four-storey building."

The union is also worried over a proposal to reduce the number of qualified teachers from 91 to 74.

Voting on potential industrial action starts next Friday and will close on June 1.