Greenpeace welcoming the opening of the new international terminal at St Pancras last year © Will Rose/Greenpeace

Almost a year ago to the day, we went along to St Pancras to welcome the opening of the new international terminal with an enormous Yes! banner. Our point was of course that the UK doesn't need new runways, we need new high speed rail links; then, as now, there were at least 100,000 flights a year between Heathrow and destinations easily reachable by train.

Since then, the Tories have not only opposed the third runway at Heathrow, they've also warned companies that they "should be very, very careful" about getting involved in any contract for a third runway as the Tories were "absolutely determined" to stop the project.

"Yes Mr Brown, we're afraid it really is that serious..."

Much as Gordon Brown would like to pretend otherwise, getting the go-ahead for Heathrow's third runway is still far from a done deal. With the Tories and Lib Dems having already rejected the proposal, the PM is now facing a growing rebellion from within his own party. Labour MPs, privately egged-on by cabinet ministers, have tabled a motion opposing Heathrow expansion in a last ditch attempt to persuade Mr Brown to change his mind - reminding him that not only will the third runway make it almost impossible for the government to hit its climate change targets, but that it is deeply unpopular with voters.

45 Labour MPs have already signed up to an Early Day Motion expressing their opposition. If this figure continues to rise, as it easily could with two weeks still to go before the motion closes, then the PM will find it increasingly difficult to defy opinion within his own party.

I still suspect I may have fallen down a rabbit hole but apparently it's true. Two weeks after formally telling the world they're opposed to a third runway at Heathrow, the Tories have issued an extraordinary warning to companies. Don't get involved in any contracts to build the third runway, they're saying, because we're "absolutely determined" to stop the project going ahead. (Oh, and they're opposed to a second runway at Stansted too.)

Gordon Brown's been in some sticky situations over his Heathrow expansion policies but yesterday he found himself super-glued to the sticky hand of Plane Stupid activist Dan Glass.