Hundreds of school trips will have to be cancelled as a result of a government deal to reduce teachers' workload, the leader of the largest headteachers' union will warn today.
David Hart, general secretary of the National Association of Head Teachers, said schools would find it impossible to release teachers for educational trips. "There is a real danger that educational visits will have to go by the board," he told The Independent in an interview on the eve of the NAHT's annual conference which opens in Cardiff today.
Under the agreement, a limit of 38 hours will be placed on the amount of time per year teachers have to cover for absent colleagues from September.
In the past, teachers released from taking lessons where the class are sitting GCSEs or A-levels or on study leave have stood in for colleagues who should be teaching younger pupils but are on school trips. As a result of the deal, they can no longer be told to do that, Mr Hart said.
"This is politically very embarrassing for the Government," he said. "There will be headlines about how the workload agreement has killed educational visits stone dead. They won't make very good reading.
"The Government is going to have to extricate itself from this situation."
Mr Hart will come under pressure to pull his union out of the workload agreement during this weekend's conference.
Delegates have tabled a motion calling for withdrawal on the grounds that the deal has not been adequately funded.
If the move was agreed, it could lead to the NAHT being "cold shouldered" by ministers in the same way that the National Union of Teachers has been. The NUT is the only one of the six teachers' unions not to sign the agreement.
NUT general secretary, Doug McAvoy, has complained that relations between it and ministers are worse than they ever were under previous Conservative governments.
However, Mr Hart said the union's executive would be "strongly opposing" withdrawal.
"In this case, pulling out would have absolutely no impact on the responsibility of headteachers to deliver the contract," he said.
"It would remove us from the very forum in which we're arguing our members' cause.
"To believe that everything in the garden is lovely and there are no problems is totally wrong but we need to be in there arguing our cause." Mr Hart said he believed the agreement would start to unravel once its second phase came into effect in September - with the limit on covering for absent colleagues.
He added that he had to convince heads they were covered by the new contractand that they would have to decide whether to bring in supply teachers or ask classroom assistants to cover - the NUT opposes this move and has threatened strike action if that happens.
Mr Hart added that problems were likely to be exacerbated in the third year of the deal - when all teachers are guaranteed 10 per cent of time away from the classroom for marking, preparation and professional development.
Many schools are considering the "Wednesday afternoon solution" where formal lessons are suspended for sport, drama, language classes and other extra curricular activities, which would be supervised by trained support staff.
"We have used unqualified staff to take these activities for years," Mr Hart said.
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