Heathrow third runway: Sadiq Khan backs legal challenge
The Mayor of London will join a legal challenge against Heathrow's third runway if it is approved by Parliament.
Four councils and Greenpeace announced they would seek a judicial review if MPs gave the go-ahead to the plans on 25 June.
"I will do what I can to stop these poor plans," said Sadiq Khan, during Mayor's Question Time.
Pro-expansion group Back Heathrow said local residents supported the plans and were aware of issues surrounding them.
Parmjit Dhanda, Back Heathrow's executive director, said: "Residents are set to benefit with 77,000 new local jobs, and they have consistently showed in independent polls that they support expansion.
"As people who live close to the airport they are aware of air quality issues, and aware of how new aircraft are getting cleaner and quieter all of the time."
Earlier this month cabinet ministers approved plans for Heathrow expansion before a Parliamentary vote.
The Mayor vowed to ensure MPs were briefed "to inform Monday's debate and vote".
He made the announcement as trade minister Greg Hands resigned his cabinet position in protest against the expansion.
Hillingdon, Richmond, Wandsworth, and Windsor and Maidenhead Councils have committed to challenging the decision if approved.
Under Mr Kahn, Transport for London has spent £320,000 providing technical support to the four councils.
Mr Khan ran for Mayor of London on a manifesto supporting expanding Gatwick Airport instead of Heathrow.
He said: "While I believe in a better Heathrow, I do not believe a bigger Heathrow is the right answer for London and I remain committed to opposing such a short-sighted decision.
"This will be a critical moment, and for the sake of Londoners affected by poor air quality, disruption from noise and the costs needed to improve transport connections I will do what I can to stop these poor plans."