Teachers are entitled by law to 10% of the timetable free for planning

Since September, teachers in Wales and England have been allowed time away from the class for "planning, preparation and assessment".

Some head teachers warn the rules could prevent PE teachers being released.

The Welsh Assembly Government said there was nothing in the new agreement which meant schools needed to change their timetables to exclude sport.

The NASUWT union said options were available to sort out any problems.

Under the new workload agreement, teachers are entitled to 10% of the timetable free from teaching in the classroom to plan lessons.

At Ysgol Friars in Bangor, the new so-called "non contact" periods means that 32 out of the 92 staff are unavailable to teach at any one time.

"We have had to cut down on the number of activities the school can take part in, as every teacher we have is entitled to two non-contact periods within the week, " said head teacher Neil Foden.

This is bound to have an effect on the health of pupils Dewi Miles, school rugby team coach

"I've just spent eight and a half hours trying to sort it out, but the knock-on is that some activities, such as sports are bound to be affected.

"It's not such a problem now because games such as rugby and football between different schools can be played after school hours, but from mid November onwards when the hours of daylight are reduced these games will not take place."

Mr Foden added that there were financial implications to the changes too.

He said the school had already spent �40,000 from its budget to employ two extra teachers as "floating supply" to try and cope with the situation.

He warned that crisis point could be reached in January and February, the months when the number of days off due to illnesses are at their highest.

His comments are backed by Haydn Davies, headteacher at Llangefni secondary school, who is also a WRU premier-level rugby referee.

The assembly government said sport should not be excluded under the new system

The new rules affect more than just sports but activities which are connected to academic work - such as theatre visits - will get priority.

Mr Davies said: "One way around this would be for each school to rota the PE teacher off on Wednesday afternoons, but so far not every school in the area has been able to do so and this means not every school team is available for fixtures.

"I don't think the ramifications of this change were worked through beforehand".

Dewi Miles, rugby team coach at Ysgol John Bright in Llandudno, said he is worried it could affect fitness and health of pupils if it school sports are hit.

Teething problems

Mr Miles said: "Because children will lose out on the disicpline of turning up for coaching sessions and games they will find something else to do - play on the computer or worse".

However, the teaching union NASUWT in Wales believes any difficulties are purely "teething problems" and the benefits to teachers far outweigh any disadvantages.

"The answer at the end of the day is in the hands of the individual headmasters," said Geraint Davies, union secretary in Wales.

Additional �70m

"There are a number of options open to them so that they can release teachers.

"This is a statutory requirement and it has undoubtebly improved the lives of teachers."

The Welsh Assembly Government said it was providing an additional �70m by next year to support the changes.

"There is nothing in the workload agreement which says that school need to change their timetables to exclude sporting activities," said a spokesman.

"We know of schools in Wales where there has been significant progress in implementing the agreement.

"They have broadened the range of experiences and learning available to their pupils within the school day, whilst meeting the requirement of the agreement".