Government plans to bring in a 'one size fits all' approach to funding will leave Norfolk's smaller schools facing significant financial challenges.

Many more federations, mergers and all-through schools are likely to be considered as they try to negotiate the changes and ensure they remain open for their communities.

As councillors prepare to discuss the government's schools funding review this week, officers have warned small primary schools with between 75 and 210 pupils 'will be faced with financial challenges' while small secondary schools 'are unlikely to be financially viable'.

The department for education (DfE) wants local authorities to introduce a single lump sum for all small schools in their areas – whether primary or secondary – in need of additional support on top of their per-pupil funding.

And it wants that amount capped at between �100,000 and �150,000.

The government claims the measure – part of a wider funding reform aimed at simplifying school funding – will help protect the country's very small schools.

But its funding reform report also admits the changes will mean only 'efficient, small schools are able to exist where they are genuinely needed'.

In Norfolk education officials have warned, while the county's smallest schools could emerge better off as a result of the changes, many more small primary and secondary schools will lose out.

Paul Fisher, assistant director of children's services for business and compliance, said: 'Our very small schools [under 75 pupils] get a lump sum somewhere in the order of �75,000 to �100,000. If we were able to set a lump sum at �120,000, the view would be that those very small schools in Norfolk would probably be financially stable in the longer term.

'But then you start thinking about which schools won't: the ones where you have not got full year groups, or those with about 210 pupils down to 75, there's going to be some financial challenges there.

'We have a big lump sum in the secondary sector up to �400,000. If we had to have a lump sum in the secondary sector of �120,000, those schools that substantially relied on a lump sum would be disadvantaged.'

The government has been accused of trying to impose another 'one size fits all' system on the country despite being repeatedly told that does not work in rural counties like Norfolk.

South West Norfolk MP Elizabeth Truss, who organised a Norfolk rural schools summit with education secretary Michael Gove last year, said she would once again be raising her concerns with ministers.

She said: 'Schooling in rural areas creates challenges that urban schools do not have to contend with. A one-size-fits-all approach is not appropriate and this was raised before with the secretary of state Michael Gove at the Rural Schools Summit I arranged in November last year.

'I want to see the traditional village school, which is such an integral part of the local community, thriving and I will press the secretary of state to ensure that appropriate levels of funding is available.'

Alison Thomas, Norfolk County Council cabinet member for children's services, said there were some protections in place to ensure school funding did not fall dramatically over the next two years.

But she said the funding reform was likely to force some changes upon schools.

She said: 'The government's planned funding reform will remove some of the protection placed on small schools in the long term and we will need to look at how we support them in the future to ensure that children in Norfolk's rural communities can access good local education.

'In the longer term, the government has said some schools may need to consider merging and federating to survive and this is a route several of Norfolk's schools are already exploring.'

Last night a DfE spokesman said the funding reform was aimed at making the system clear and transparent through a more simple structure.

The government's school funding reform, which includes a number of other measures aimed at simplifying the way schools receive money, will be discussed at this Thursday's children's services overview and scrutiny committee.