Boris Johnson gave a firm warning to those in Government who want a third runway at Heathrow: "Forget it - it will not be built."
The Mayor of London, in his speech about the future of flying in the south east said said Heathrow was failing as a hub airport and Britain is 'losing out' as a result.
He claims the Governement has better options - to expand Stansted or to build a new airport in the Thames Estuary.
But what of the timings of this latest attack, coming so close to his party's annual conference? Our Political Correspondent Simon Harris reports.