A fresh row has erupted over the controversial incinerator proposed for Norfolk, after councillors claimed they had been kept in the dark over the rising cost of possible compensation for the plant.

A decision on whether to grant planning permission for the incinerator at Saddlebow, which the county council awarded a contract to Cory Wheelabrator to run, has yet to be made by communities secretary Eric Pickles.

That delay has infuriated the administration at County Hall, who say their budget planning has been made much more difficult because, if planning permission is not secured, Cory Wheelabrator could claim compensation.

And papers presented to a recent meeting of Norfolk County Council's cabinet revealed that the cost of that compensation would increase after May 1.

The figure is currently a potential £26m, but the report by interim head of finance Peter Timmins shows after the start of May, that will increase by £5m to £31m.

The council is building up a 'war chest' of £19m, but councillors who have opposed the incinerator said that figure should have been revealed before a crucial vote on whether to press ahead with a revised project plan for the incinerator.

Last October, the council voted by 40 votes to 38 to agree a revised project plan for the £500m plant and anti-incinerator campaigners say that vote might have been different if councillors had known the possible compensation cost would increase in May.

Retired solicitor John Martin, from Great Witchingham, emailed David Harrison, cabinet member for waste and the environment, to make that point.

Mr Harrison replied that the issue was identified in a public report on October 29 last year and added: 'The members were all e-mailed about the revised project plan and its various scenarios before the full council meeting'.

But Mr Martin then emailed other councillors to ask which of them were aware that the possible compensation would rise to £31m after May.

Among those who said they were not aware of the uplift were Fred Agnew (UKIP), Andrew Boswell (Green), Brian Long (Conservative), Richard Bird (Independent), Jason Law (Conservative), Stan Hebborn (UKIP), Colin Aldred (UKIP), John Dobson (Conservative), Paul Gilmour (UKIP), Alexandra Kemp (Labour) and Tim East (Liberal Democrat).

Mr East, who represents Costessey, said: 'Had officers made councillors aware of this possibility concerning this potential uplift in their report before its meeting on October 28, I think the decision may well have gone the other way.'

The council said in the report to full council, it stated that 'the actual contract price at the time of financial close could increase or decrease'.

A spokesman said, in the cabinet report for the following day's meeting, it stated that the compensation figure would 'have to be revisited' if the project continued to be delayed beyond spring this year.

The council said those details were available before the full council meeting, where the vote was taken and that group leaders were briefed ahead of the council debate, while there were more details in 'pink papers' which only members were able to see.

The spokesman said a report to cabinet in November also referred to the compensation payment increasing from May 2014 onwards.

They added putting a figure on the potential size of the increase was not possible at an earlier stage and that the £31m was an indicative figure used for budget setting.

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