The Mayor of London met with the MP for Richmond Park last week to talk about their shared opposition to a third runway at Heathrow.
While there, it is understood the pair talked about Westminster rumours that Goldsmith was willing to resign his seat, causing a by-election that would enable Johnson to return to parliament and fight against government policy on airport expansion in the House of Commons.
Yesterday Goldsmith told the Mail on Sunday that the pair discussed “all sorts of possibilities” to oppose development at the west London airport.
But a spokesman for Boris Johnson said the by-election story was “without doubt fanciful”.
“It’s no secret the Mayor opposes the building of a third runway, he was re-elected opposing any such notion, he’ll continue to oppose any such notion, and he’ll be doing it as Mayor of London.”
Last week Johnson, who favours a new airport in the Thames Estuary, declined to rule out a return to parliament, while Goldsmith repeated his pledge to force a by-election if the government changes its policy on Heathrow.
The Mayor also directly criticised David Cameron’s decision to move Justine Greening, a noted opponent of Heathrow expansion, away from the Department for Transport in the recent cabinet reshuffle.