A public inquiry into plans to build a controversial incinerator on the edge of King's Lynn will be held in Norfolk, Communities Secretary Eric Pickles' department said last night.

But a spokesman for the department said it was still too early to say when the inquiry would be held – only that it would be sometime next year.

The secretary of state called in the planning application after his department received nearly 6,000 letters which is one of the most ever received for an application.

A spokesman for the Planning Inspectorate was also unable to shed any light on when the inquiry would be held because it 'depends on lots of things'.

But he said: 'It was only called in on Thursday so there is not a lot happening at the moment because we are waiting for a file to come from the department of local communities and local government.

'Once we have received this we will write to all the parties involved, including Norfolk County Council and the developer.

'What we will be asked is for possible dates for any inquiry to be held and if we have an inspector available on any of those dates then that day will be fixed.

'We will then need to look at whatever length is felt is needed for the inquiry. Even after we've gone through this and had the inquiry, the recommendation will be sent to the secretary of state for him to make a decision and there is no deadline for when this has to happen.'

Norfolk County Council awarded the contract to build the incinerator, known as the Willows Power and Recycling Facility, to Anglo-American consortium Cory Wheelabrator last year.

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.

Environment secretary Caroline Spelman has already announced the approval of �91m in PFI funding to Norfolk County Council to go towards the cost of the proposed incinerator in Saddlebow.

However West Norfolk council intends to challenge Ms Spelman's decision to approve the PFI funding.

The council claims Ms Spelman broke her own guidelines in awarding the money because there is not a 'broad consensus of support' for the �500m incinerator. A poll carried out in West Norfolk saw 65,000 people vote against the building of the plant.