Controversial plans for changes to an incinerator near Braintree have been given draft approval.

The Environment Agency (EA) had previously refused an application for the facility at the former Rivenhall airfield, which would operate with a 35 metre high chimney. But it is now proposing to accept changes from applicants Gent Fairhead and its operating partner Indaver, which will apply stricter limits on the emission of oxides of nitrogen, sulphur dioxide and lower limits for heavy metals. The companies' application also seeks to change the primary means of controlling nitrogen emissions. The EA says these changes make a 35 metre high stack acceptable.

However Nick Unsworth of campaign group PAIN (Parishes Against Incinerator) said he could not understand why the Environment Agency (EA) had changed its mind over a plant that can burn 600,000 tonnes of waste a year.

Mr Unsworth, who sits on Braintree District Council, said: "Braintree District Council have just issued a climate emergency and this seem at odds with that. "I don't understand why the Environment Agency have done this with a lower stack. "It seems at odds with all the current thinking. We will carry on fighting this."

The company had aimed to gain permission by means of operating with a 58 metre high chimney which had been granted an EA permit. But planning permission for this was refused by Essex County Council earlier this year.

A statement from the EA said: "After carefully considering the application over the last 12 months, including all received consultation responses, we are now proposing to accept the changes requested by the company. "We are of the opinion that the proposals will provide for an equivalent level of environmental protection as that afforded by the current permit.

"As a result, we are proposing to vary the current permit conditions to incorporate the requested changes."

Gent Fairhead say the new plant would divert waste from landfill, recover valuable materials from waste and produce enough electricity to power more than 60,000 homes. The EA says after carefully considering the application over the last 12 months, including consultation responses, it is proposing to accept the changes requested by the company.

It will now hold a period of public consultation on its proposed decision, which starts on 9 January and will end on 6 February.

A spokesperson said: "We are keen to hear from anyone who wants to have their say on our proposal before we make a final decision.

"Our draft decision document sets out in detail the reasoning for our current proposed decision.

"The draft decision document also provides details of our consideration of those issues/concerns raised by the public during the consultation earlier this year."