A campaign group opposed to the proposed expansion at Stansted Airport has called on district councillors to “convert words into deeds” by turning down an application to increase a cap on passenger numbers.

Stop Stansted Expansion (SSE) said it welcomed the resolution by Uttlesford District Council (UDC) to declare a climate and ecological emergency and to commit to achieving net zero carbon status by 2030.

The resolution was approved by a majority of councillors on July 30.

SSE said, however, that the challenge was now is for the council to "convert words into deeds", and demonstrate their commitment to tackling climate change.

Peter Sanders, SSE chairman, said: "It is now time to convert words into actions. The council's declaration of a climate emergency would be a hollow gesture if it were now to approve the expansion of the airport to 43 million passengers per annum (ppa), almost equivalent to today's Gatwick."

According to SSE, Stansted Airport is the largest single source of carbon dioxide (CO2) emissions in the East of England. This year, the group said, Stansted will produce an estimated 2.1 million tonnes of CO2 - which increases to the equivalent of 3.8 million tonnes when radiative forcing is taken into account.

The Intergovernmental Panel on Climate Change recommended that aircraft CO2 emissions should be multiplied by between two (the radiative forcing factor) to reflect the greater climate impact of CO2 emissions at high altitude as well as the impact of emissions of other greenhouse gases from aircraft engines.

Mr Sanders added: "The need to tackle climate change is an urgent challenge which transcends politics and we owe it to our children and grandchildren to do everything in our power to prevent a climate emergency becoming a climate disaster. Our local council now needs to rise to this historic challenge.

"We very much hope that on an issue as important as this for future generations, councillors will agree with SSE that reducing the adverse environmental impacts of aircraft carbon emissions is now a high priority matter and the right thing to do. History will remember those who fight for what they believe to be right long after it has forgotten those who gave way on such a vital issue."

UDC's planning committee is set to revisit Stansted's application to increase its annual passenger cap from 35million ppa to 43 million in the next few months, after a meeting of full council held in June declined to issue a final approval notice.

The previous Conservative administration had originally granted permission last November but the final approval notice was withheld following a requisition notice from Residents for Uttlesford, which is now running the council.

An airport spokesman said: "As our application makes totally clear, Stansted is committed to sustainable and responsible growth. This means our proposal to serve additional passengers would be delivered while maintaining the existing cap on the number of flights permitted and with a smaller, legally-binding noise footprint than is currently required.

"In addition, we are already accredited as a carbon neutral airport, and are already welcoming the next generation of aircraft that are up to 25 per cent more fuel efficient. This is why the industry has been able to see continued passenger growth without a similar increase in emissions.

"Aviation is a global business, which is why the Government and industry are focused on reaching international agreements instead of local quotas. London Stansted fully supports this approach and plays a leading role in Sustainable Aviation - the coalition of UK airlines, airports, manufacturers and air navigation service providers - to set out how UK aviation can meet both its climate commitments and growing passenger demand."