A long-sought debate over the proposed Norfolk incinerator could happen by the end of the month, as a group of councillors presented what they say is evidence it would be cheaper to send waste to be burned in Amsterdam.

But the leader of Norfolk County Council hit out at a call for the government to pull the plug on the money to bankroll the proposed King's Lynn plant, saying that would burden county taxpayers.

A group of councillors, from UKIP, Labour, Conservative and Green groups, unveiled two reports they say show it would be more cost effective to send waste to an existing incinerator in Amsterdam than to build a new one near King's Lynn.

Doing that in the short-term, they argued, would give the authority time to find better solutions.

While George Nobbs, leader of the council, agreed a full council debate on the incinerator was needed, he questioned the rationale of asking the government to take away the £169m waste credits.

The group of councillors, including UKIP leader Toby Coke and Conservative John Dobson, revealed how a company called Rebel Group had offered to deal with the county's waste by shipping it to Amsterdam – for less than the cost of council contractor Cory Wheelabrator incinerating it in Norfolk.

Mr Coke revealed two reports, one by Dr Chris Edwards, a senior fellow at the University of East Anglia, and one by waste industry consultants Eunomia.

Mr Coke said the reports illustrate 'the folly of going ahead with the Willows incinerator project.'

He said the report by Dr Edwards, which does not explicitly state the Rebel Group offer should be pursued, concludes there is no financial incentive for the county council to terminate the contract with Cory Wheelabrator while the government continues to offer waste credits.

Mr Coke said that showed the council must have a vote to call for the government to withdraw those waste credits and to reject a revised project plan, with the current one due to expire at the end of the month.

Mr Coke said: 'If cabinet decides to uphold a council decision to reject the revised project plan then compensation costs are capped at £20.3m.'

The council is waiting to hear whether the secretary of state will ratify its decision to grant planning permission. Mr Nobbs said afterwards: 'It is hard to argue with Mr Coke that the time has come for this matter to be resolved once and for all.' He said he had asked the chairman to call a full meeting of the council later in the month – specifically to consider two reports the cabinet previously commissioned, the waste and minerals strategy and to make a recommendation on the issue of the revised project plan.

But he added: 'I cannot entertain the proposal of sabotaging the waste credits as one I could have sympathy with. The financial burden this council has to carry is massive enough without adding a massive self-inflicted wound.'

He warned the withdrawal of the waste credits would not end the contract and said: 'We would still be locked into the contract agreed by the previous administration, but the people of Norfolk would be £169m worse off.'