A troubled Great Yarmouth primary school is proposing a compulsory 45-hour week to help underachieving youngsters meet national curriculum targets.

Greenacre Primary School has gone through eight head teachers in as many years, lies in a deprived area of Great Yarmouth and has a historical reputation as a 'failing' school among Yarmouth's teaching community.

So when new head teacher Bill Holledge, 33, took the reigns of the school in September 2011, he was determined to make quick improvements to shake this reputation and raise learning standards.

County council bosses suggested the school look at the academy route to improvement, and introduced Mr Holledge to multi-millionaire Theodore Agnew - a willing sponsor.

Arrangements were made, and after a consultation process - which parents dispute - the academy move was announced last month along with radical changes to the school timetable.

Under the new regime, the school day for pupils aged nine to 11 would end at 6pm as of September 2012.

The extended day will include extracurricular activities from horseriding to IT, and supervised homework time.

Parents are concerned that the plans will eat into family time and leave their youngsters worn out - more than 200 have signed a petition against the move.

And the plans have already drawn a mixed response from Norfolk's education professionals, with Yarmouth teachers seeing the learning virtues of a longer week but unions worried that change has been 'forced' upon parents.

Colin Collis, Norfolk county secretary of the NASUWT, the largest teachers' union in the UK, said: 'You will end up with very tired youngsters who will perform less well - children should be able to be children after school.'

He said the extended timetable should be optional – 'otherwise parents have a very stark choice' of conforming with the regime or finding a new school for their child.

Mr Agnew has pledged to give Greenacre at least �40,000 annually for the next five years and helped fast-track improvements to buildings, including the judo room, with the county council.

Mr Collis says academies are leading to a higher staff turnover with many teachers 'burnt out'.

'This is pressing a market philosophy for education and it will hurt the education system,' he said.

But leading teachers in Great Yarmouth, who know the challenges of the area, say the proposed 45-hour week could help bring about improvement.

John Catton, consultant head teacher of Great Yarmouth High School, said: 'We have an issue of general underachievement in education across the town and this will help us to deal with it.

'I've no doubt at all that the additional time and plans Greenacre have for using the time will be beneficial to the Yarmouth community, as there are additional opportunities there for social and academic development of young people.'

And Alison Hopley, head of Alderman Swindell Primary School, agreed that Greenacre was in need of radical change.

'As long as I remember, since 1984 when I began my teaching career, Greenacre has been a failing school,' she said. 'Bill Holledge has taken the bull by the horns and if I were in his shoes I would do exactly the same thing.'

She said the proposed curriculum was well planned and would help children several years behind the attainment levels they should be at.

'He's got to put in a short-term, intensive package or you don't stand a chance,' she said. 'It's giving children opportunities – art, dance and music – that are the sort of thing middle-class children would be doing anyway.'

She said she was very sceptical of academy chains turning education into a business model, but approved of sponsor Mr Agnew as he was 'independent' and had a local interest and a track record of investment in learning.

Aylsham-born Mr Agnew founded an insurance firm in 1989 and made his fortune with a string of more than 20 successful companies.

He is a prominent Tory party donor, having given more than �130,000 in recent years, and education secretary Michael Gove has hailed the plans for Greenacre as 'brilliant'. He is also a non-executive director at the Department for Education but unions have questioned his involvement with the school.

Scott Lyons, assistant Norfolk county secretary of the National Union of Teachers, said: 'One of my fears is it stinks of nepotism. I would question who is going to be offering the horseriding lessons. I wouldn't be surprised if it were a very close circle using state money.'

He added that late classes may begin as enrichment but end up being more maths and English lessons 'to get the levels up – which is narrowing of the curriculum'.

Parents are split on the issue and Great Yarmouth MP Brandon Lewis acknowledged the 45-hour week is a radical move.

'It's a big change and that often causes controversy,' he said. 'But it's what a lot of people in private education pay a lot of money for and people in that area really need it. I support the school in giving it a go – bear with it and see how children go with it.'

He hoped for dialogue between parents and the school and said the model could pave the way for national improvement as 'we need to pull our educational boot straps up in this country, test the boundaries and try something new'.

Phil Hardy, Norfolk County Council's deputy cabinet member for children's services, said: 'We recognised there were areas of the county that needed a change in order to boost aspirations and raise educational achievement, and academies have the potential to transform learning within their communities by developing a new ethos, new subjects and new ways of working.'

Mr Holledge is not able to attend tonight's meeting, but in a letter to parents said he was happy to meet those with concerns on an individual basis.

The open meeting at Great Yarmouth Town Hall starts at 6pm.