Campaigners against one of the biggest and most expensive projects the south east has ever seen have an unexpected ally - a gas plant on the Isle of Grain in north Kent.
The plant has just secured a four-year deal to buy up to three million tonnes of liquefied natural gas which could secure the energy needs of three million British households.
But the plant is right in the middle of what could be Boris Johnson's new Thames Airport. And the possibility that the site could be demolished or relocated is being hailed as a nail in the coffin for the Mayor's plans.
Simon Harris has been looking at the arguments for and against.