THE London mayoral candidates of the four major political parties have signalled their opposition to Heathrow expansion ahead of the May 6 poll.

West Londoners have faced the uncertainty over a third runway at the major international hub for years, but in the latest legal challenge at the Supreme Court in December 2020, judges ruled that the project could still go-ahead.

Residents neighbouring the airport whose homes will be demolished in the event of the expansion described the move as the 'worst Christmas present ever'.

Speaking to campaign group No 3rd Runway Coalition, the four mayoral front runners however voiced concerns over its environmental impact such as air and noise pollution that would extend to hundreds of thousands more Londoners for the first time.

Current London Mayor and Labour Party candidate Sadiq Khan has previously supported legal action against the expansion and said a new runway at Heathrow would have 'disastrous consequences' for the environment.

He said he will continue to lobby the Government to reverse their plans, adding: "A third runway would make air quality worse for those who live near the airport, would undermine efforts to combat the climate emergency and risk turning the tide of all the progress we've made to tackle toxic air in London over the past five years."

Conservative candidate Shaun Bailey also was clear in his opposition to Heathrow expansion on environmental grounds warning the country's carbon neutral target by 2050 would be 'blown out of the water' if the runway goes ahead.

He said: "Heathrow expansion would mean an extra 700 flights per day, which is 285,000 additional flights a year which is far too many.

"The extra noise will mean that 300,000 new Londoners will also be affected by high noise levels and nobody wants that.

"When we talk about air quality, Nitrogen Dioxide, Heathrow is a real hotspot for that poor air quality, we want to push that down, not push it up."

Meanwhile, Green Party candidate, Sian Berry, said the Greens have been at the 'heart' of campaigning against Heathrow expansion for decades and would not support a new runway at any airport.

She said: "We've seen it off before together and Greens are rock solid on this."

"We are in a climate emergency.

"We need to cut down air pollution, including from traffic to and from the airport and so we can invest instead on transforming our economy and the jobs we need for a secure future."

Speaking about other airports in London, Ms Berry also vowed to shut down London City Airport to use that land 'for what London really needs.'

Liberal Democrat candidate Luisa Porritt also said she's going to 'fight this all the way' citing the climate emergency and impact on Londoners as key reasons.

"The noise and pollution impact on residents in South West London are simply going to be unacceptable.

"It's bad enough already we cannot make this worse," she said.

Ms Porritt also pushed the case for a local-led recovery to the COVID pandemic and that the economic case for airport expansion anywhere 'has completely collapsed'.

West London communities have been hard-hit over jobs and unemployment during the pandemic due to the decline of the aviation industry from COVID.

In the lead up to the election, West Londoners are also calling on candidates to commit to the creation of 60,000 green jobs, including for low-income and diverse communities, to offset the job losses from Heathrow's COVID-19 crisis.

Mr Bailey's manifesto commits to 11,000 green jobs to help London become a 'net-neutral' city and 'build back better' after the pandemic.

It particularly mentions sectors such as green tech and local energy production.

Ms Berry's manifesto pledges to support Heathrow workers and surrounding businesses that rely on the airport with a 'just transition' policy to create jobs and training in the local communities where flying is reduced.

It adds: "This will be done through targeted Green New Deal investments in industries and job markets that can sustainably offer high-quality employment opportunities in areas such as renewable energy, housing stock improvements, education and community support."

Green jobs are also included in manifestos for Mr Khan and Ms Porritt.