TEACHERS could vote to take industrial action, amid claims that staff shortages are causing them stress.

The National Association of Schoolmasters and Union of Women Teachers (NASUWT) is in talks with its Middlesbrough members, along with members of the National Union of Teachers (NUT) over whether to take a ballot.

If the borough's teachers agree to it, they will be asked to vote on a work-to-rule option, under which they would not have to cover colleagues' absences.

The ballot has been suggested after 110 year eight pupils at Brackenhoe School, Middlesbrough, spent three days at home due to a chronic teacher shortage.

In what are described as "extraordinary circumstances", as many as nine of the school's 39 staff have been absent for periods of the past three weeks.

Headteacher Martyn Berry attributed this to "an unusual and unprecedented incidence of sickness", as well as two unfilled vacancies.

Last night, he expressed confidence that the children would be able to return for the rest of the week, although he admitted that one of the three supply staff on which he was relying was unconfirmed.

Hans Ruyssenaars, of NASUWT, said the stress of extra work was making teachers ill.

"I can see similar things happening in other schools as there are a few more that are close to the edge.

"Quite obviously, those teachers left behind will work twice as hard. In the long term, this affects their health."

Mr Ruyssenaars said if Middlesbrough teachers are in favour of a ballot, those in Hartlepool, and possibly elsewhere, will be consulted.

He said: "I expect to take a decision over whether to go ahead within the next week."

Mr Berry praised staff at the 550-pupil school for their commitment.

He said: "The reason we have managed to minimise our problems is because all staff in all unions have not refused to undertake other duties."

A spokesman for Middlesbrough Borough Council said: "Middlesbrough is not immune to a national shortage of core subject teachers.

"The situation here is nothing like that facing schools in London and the south, but we are not complacent, and we are looking at introducing a long term recruitment and retention package."