Oxfordshire MPs have called on County Hall to rethink the plan to build a £100m incinerator as the answer to the county’s waste problems.

The MPs made their concerns about burning waste known as new fears emerged that Oxfordshire could end up with two incinerators because of the way that Oxfordshire County Council has handled the issue.

The Tory MP for Wantage, Ed Vaizey, risked embarrassing the ruling Conservative group at County Hall by coming out against the council.

The county council wants to see an incinerator for the county’s waste built either at Ardley, near Bicester, or at Sutton Courtenay, near Abingdon.

More than 20,000 people across the county have signed a petition opposing incinerators, amid claims that the health implications of modern incinerators have not been properly investigated.

It is likely to be a major issue in the county council elections taking place in June.

But Mr Vaizey delighted campaigners by telling The Oxford Times that he had decided that incineration was a mistake.

And he called for the county council to go back to the drawing board and reconsider better technologies for dealing with waste.

Mr Vaizey said he believed that the county council strategy of staying “technologically neutral” in the selection process — instead of favouring the most environmentally friendly methods of waste disposal — had resulted in companies coming forward with “the cheapest and easiest solutions, rather than the best for Oxfordshire”.

Tory MP for Banbury Tony Baldry warned that Oxfordshire could end up with two incinerators, one taking local waste and the other millions of tonnes of waste from other parts of the country.

He said a county council planning miscalculation could see the county finish up with one plant in the north and one in the south.

Mr Baldry, who said he was neither for nor against the incineration option, believed County Hall had created potentially serious problems by inviting two waste companies — Viridor at Ardley and the Waste Recycling Group (WRG) at Sutton Courtenay — to seek planning permission, with only one to be awarded the contract to burn 300,000 tonnes of waste a year.

He believed “the losing company”, if it acquired planning permission, could still end up building a plant, making hefty profits from taking waste from other parts of the country.

Mr Baldry said: “This is a real risk and it would really raise real anger among local people.”

The MP said that when he approached Viridor to discuss such a situation arising there was “a deafening silence”.

A spokesman for Viridor told The Oxford Times the company had not considered what it would do if it failed to win the council contract. He said: “This is not a scenario we have considered. We would not rule anything out at this stage.”

Oxford East MP Andrew Smith said: “I'm against incinerators and am very concerned about their environmental impact.”

Oxford West and Abingdon MP Dr Evan Harris said: “The county's process should have been to identify the most environmentally-sound option, not the cheapest.”

Henley MP Dr John Howell, a member of the county council cabinet up until recently, backed County Hall’s waste strategy. He said: “The tender process was an open one. The assessment was a finely balanced one in terms of environment implications.”

Witney MP David Cameron, the Conservative leader, said the decision on what form of waste disposal should be adopted in Oxfordshire was down to the county council.

Oxfordshire County Council initially did not rule out building two incinerators, but it now believes one would meet the county’s waste need. The two incinerator planning applications are expected to decided by County Hall in July.

A spokesman for the county council said: “The council, in determining these applications, will need to have regard to Government policy, which urges that each county is self- sufficient in providing for the treatment of its own waste. This would have real implications with regard to the likelihood of more than one incinerator being built in terms of commercial viability.”