Environment secretary Caroline Spelman has released millions of pounds to fund the building of an incinerator in Norfolk.

Mrs Spelman had withheld government funds from Norfolk County Council because of concerns about the proposals for an incinerator on the outskirts of King's Lynn.

But she has today awarded the waste infrastructure grant and in a letter to Norfolk County Council leader, Derrick Murphy, confirmed the project meets her criteria for the grant.

She said that a promissory note from Defra (Department for Environment, Food and Rural Affairs) to Norfolk County Council, which will be worth up to �91 million over 25 years to Norfolk's council taxpayers, will be issued.

However she adds: 'I am sure that you share my continuing concern that the project is generating such strong negative feelings locally.

'While I recognise that King's Lynn and West Norfolk Borough Council may continue to object to the project through the planning process, I hope that if it were to proceed, all local authorities and the contractor will put fresh effort into working constructively with local interests to maximise the project's potential benefits for sustainable waste management, local employment and regeneration, and to minimise reasons for local concern.'

Reacting to the letter, Bill Borrett, cabinet member for environment and waste, said: 'We are pleased the Government has decided to support this project, which is of significant strategic importance for the people of Norfolk, and that the Secretary of State is satisfied that it meets her criteria for a grant.

'The grant represents the largest amount of central Government funding for a single project that this council will have ever received.

'It will substantially reduce the cost of a proposed new service for dealing with Norfolk residents' waste, making it excellent value for money – and very good news for the county's council taxpayers.

'It also reflects the Government's opinion that projects such as this will help the country meet its European landfill diversion targets.'

Mrs Spelman had announced in November she was withholding the grant and told County Hall she wanted to see more evidence of 'broad support' for its proposed waste strategy.

That led to a number of district councils writing letters to Mrs Spelman supporting the waste strategy, though West Norfolk Council leader Nick Daubney and some opposition leaders on district councils pleaded with her not to be swayed.

Cllr Borrett continued: 'This is another, very positive step forward for this important project, but with the planning and environmental permitting processes under-way, and contract arrangements for the new service still to be finalised, there is still some way to go.

'I understand the Secretary of State's concern to see us 'work collaboratively and constructively with local interests to maximise the project's potential benefits for sustainable waste management, local employment and regeneration, and to minimise reasons for local concern'. We will do our very best to ensure this happens.

'Norfolk's joint waste strategy is also much broader than an energy from waste plant which will, after all, deal just with that part of our waste that's left over.

'Our strategy is really a much bigger picture that requires us all to work hard to reduce, reuse and recycle as much as we possibly can and we want to continue working with all our local government colleagues in Norfolk on this very important agenda.'

Elizabeth Truss, MP for South West Norfolk, and Henry Bellingham, MP for North West Norfolk, are both opposed the incinerator.

Ms Truss said: 'I am extremely disappointed by this decision. I wanted the �169 million [grant] used on a project that has support.

'The scheme in its current format does not command the support of local residents, it is too large and in the wrong location.

'Sixty five thousand people voted against it at last year's referendum and I have repeatedly advocated the creation of a pan Norfolk waste operation to deal with waste more efficiently. I will continue to press for a rethink in the planning process.'

Mr Bellingham has said a public inquiry was necessary. He continued: 'I would hope very much Mr Pickles will call it in, appoint an inspector to hear it in a public inquiry and then everybody will have their say.

'It is currently going through the county council planning process. Their planning committee will deliberate on the application. Now I don't think anyone in Norfolk would have any faith in that arrangement.'

County councillors have already unanimously agreed they need to visit the site of the proposed plant, which will cost more than �500m, before making a decision.

The planning regulatory committee has yet to fix a date for when to head to Saddlebow but chairman John Rogers has urged members not to get embroiled in conversations about the plant in advance.

A committee report said: 'At the time of writing, 2,639 representations had been received, of which 2,550 (96.6pc) have objected to the proposal. Given this level of objection, the proposal can be considered to be controversial.

'The site visit would be a fact-finding visit to enable members to note relevant features pertaining to the site and to gain an appreciation of the scale of the proposal in the relation to its surroundings.'

The county council says the plant is needed to prevent the county's waste having to go to landfill. It says it will save millions of pounds a year.

But in a poll conducted by West Norfolk Council, 65,000 people said they did not want the plant.

Anti-incinerator campaigners last month attempted to secure a judicial review into the process by which the county council agreed to award a contract to waste company Cory Wheelabrator but a High Court judge dismissed their attempt.