Pupils are suffering in the classroom because of the millions being spent by schools in Norfolk hiring supply teachers.

That was the claim today from a teachers' union after it was revealed that during 2012/2013 Norfolk's primary, secondary and special schools paid out £9.2m on supply staff – up by more than 12pc on the previous year.

The figures have also led to concerns that Norfolk schools are struggling to attract teachers because of their remote locations and low Ofsted ratings, meaning supply cover having to be drafted in more regularly.

One headteacher said his school had been forced to recruit full-time staff from Canada, such was the problem.

Mike Smith, county division secretary for the National Union of Teachers, said: 'The use of temporary staff to replace permanent staff must have a negative effect on the learning of the pupils.

• Click here to view the top and bottom spenders in the region

'Parents should be very concerned that there is such a need for supply teachers.'

Mr Smith believed that more was being spent on supply cover because teachers were leaving the profession due to 'unreasonable demands being made by Mr Gove and Ofsted'.

He added: 'Those coming into the profession are only staying for an average of five years. They find the demands unacceptable and the prospect of working in a classroom until they are 68 years old as ludicrous.

'To reduce the demand for supply teachers we will need a change in government and Ofsted.'

Top spender, Downham Market Academy, formerly Downham Market High School, forked out £339,154 during the last academic year, almost tripling the amount of £109,942 which they spent during 2011/2012.

Headteacher Jon Ford said the figure was so high because of the way staff was coded within the school's supply budget.

He said: 'As it is difficult to attract teachers to the west of Norfolk, we use a range of tactics including sourcing teachers from Canada via Engage, a supply agency and recruitment firm.

'We do have a significant number of staff from overseas to ensure that we have a full complement of fully trained and able staff. Unfortunately, the way we code their salaries, it appears that they are supply teachers.'

The school is now fully staffed but Dr Ford said it was in a 'phase of rapid improvement', leading to 'significant staff turnover'.

He added: 'I firmly believe Downham Market Academy has a strong staff team and is in great shape to continue its rapid improvement.'

Gerard Batty, headteacher of Hellesdon High School, in Norwich, said a conscious decision was made three years ago to reduce the amount spent on supply teachers at the school to zero. During 2011/2012 the school spent £32,235 on temporary agency staffing cover but during 2012/2013 the school achieved its 'zero' goal.

Mr Batty explained that the school still 'infrequently' used supply teachers, but only to cover long-term absence, and that cost came under a separate budget heading.

He said: 'There are very good supply teachers out there and I would not want to say anything against what they do but we found for us that continuity works.

'Saving money is second – it's about giving students continuity.'

The money saved has been used to employ five permanent cover supervisors, responsible for covering absent teachers and adding extra teaching support in the classroom.

During 2012/2013 the cost of supply teachers was highest in primary schools, at £5,896,388 (just under 63.5pc of the total amount spent on supply teachers in Norfolk that academic year), only slightly more than the previous year's figure of £5,890,999.

In 2012/2013, secondary schools spent £3,156,232 (just under 34pc of the total amount spent on supply teachers in Norfolk that academic year), revealing a 41.4pc rise from the previous year's figure of £2,232,126.

But the highest jump, although only making up around 2.5pc of the total amount spent during 2012/2013, was special needs schools. This spending increased by 46.6pc – the £158,982 spent in 2011/2012 increased to £233,204 in 2012/2013.

During 2011/2012 the total amount spent on supply teachers in the county was £8,282,108 – more than £1m down on the most recent year's figures.

Norfolk schools have been responsible for their own finances since 1988 and it is the responsibility of governors and headteachers to make a decisions on budgets.

Schools can obtain financial benchmark information from the Department of Education to compare expenditure with similar schools.

A spokesman for Norfolk County Council (NCC) said: 'Schools spend their money to get the best value for their pupils' education. There is also a growing number of supply agencies for schools to use.'

NCC said the cost of a supply teacher ranged from £180 to £230 a day. Deputy heads, headteachers and senior staff would be at the higher end of the scale and the average cost was £200 a day. The Department of Education said a newly-qualified teacher would earn a minimum of £21,804 but could start on more depending on previous experience.

The figures were obtained following a freedom of information request. The responses from NCC do not include foundation schools or academies.