A government decision on the positioning of a new runway for the south-east of England may not come early this week as had been widely anticipated.
Government sources expected the cabinet to decide on Tuesday which of three airport expansion options to back, but it is now believed the final decision will be made later in the month.
Insiders claim No 10 is nervous about the decision influencing the by-election in Witney, Oxfordshire, on Thursday, the Sunday Times reported.
A cabinet sub-committee chaired by prime minister Theresa May is expected to recommend which plan to go for – a third runway at Heathrow, expending one of the London hub’s existing runways or a second runway at Gatwick – with the final decision then made by the full cabinet.
This followed intervention by former chancellor George Osborne who claimed the economic case for expanding Heathrow was “overwhelming”.
Business, energy and industrial strategy minister Greg Clark was also reported to be the biggest supporter of Heathrow within the cabinet because his Tunbridge Wells constituency is affected by aircraft overflying to and from Gatwick.
Weekend media reports suggested that ministers have asked the West Sussex airport for a list of “compromise” options for expansion should it not get the go-ahead for a new runway.
One possibility could involve a package of rail and road improvements. Another suggestion is that while May would give the immediate go-ahead to Heathrow, she could leave open the possibility of Gatwick expansion within the next decade.
Some insiders were reported as saying the challenges involved in building a third runway at Heathrow, including whether to put the M25 in a tunnel or divert it, are so large that Gatwick could still open its £7.1 billion second runway first, even if it had to wait for years before it received permission.
Heathrow Hub, the independent group that has proposed doubling the length of Heathrow’s existing northern runway, placed double page adverts in weekend newspapers arguing that its plans is £6 billion cheaper than a third runway and could be operational by 2023.
Meanwhile, climate change campaigners predicted an escalation in direct action protests if Heathrow is allowed to build a third runway.
A previous attempt to build a third runway under the Labour government became the focus of an environmental campaign, with a protest camp established outside the airport in 2007 and a string of high-profile stunts by activist group Plane Stupid.