Brexit fallout 'cast doubts on Heathrow runway expansion'
Brexit "must cast doubts" on whether Heathrow Airport will get a third runway, the chairman of the anti-expansion group Hacan has said.
According to John Stewart, if Boris Johnson follows David Cameron as prime minister his opposition to Heathrow expansion leaves it "up in the air".
But Heathrow's boss John Holland-Kaye said its expansion "is the right choice for a stronger Britain".
The Department for Transport (DfT) said it was "committed" to the project.
The government was to decide on whether to expand Heathrow or Gatwick in July.
A statement from the DfT said: "The government remains fully committed to delivering the important infrastructure projects it has set out and will also continue to take forward important legislation put before Parliament in the Queen's Speech."
The Airport Commission had recommended last July for a third runway at Heathrow - a new 3,500m runway north of the two existing runways - at an estimated cost of £18.6bn.
But in December the government delayed its decision saying further work on noise, pollution and compensation needed to be carried out.
Many campaigners have cited traffic pollution from vehicles, noise pollution from flights and having to sell their homes as reasons to halt Heathrow's expansion.
Mr Stewart said: "Brexit must cast doubts on whether a third runway at Heathrow will ever be given the green light.
"The prime minister and the chancellor have lost the fight of their lives and 'outers' like Boris Johnson, who is fiercely opposed to Heathrow expansion, have won.
"At the very least, a decision on a new runway must now be up in the air."
Mr Stewart wants the new prime minister to "look again at its desirability, its deliverability and the cost".
"The government had pencilled in 7 or 8 July to announce its runway decision.
"It would be surprising if a lame-duck prime minister risked further splits within the Conservative party by making such a controversial decision just weeks before he leaves office."
But Heathrow Chief Executive John Holland-Kaye said: "Now more than ever, people across Britain are counting on the government to take bold decisions that show we are a confident outward looking trading nation.
"Heathrow is the right choice for a stronger Britain."