IAG boss Willie Walsh has threatened to pull British Airways out of Britain and focus on expanding in Ireland or Spain if the ongoing debacle over Heathrow's third runway does not soon come to an end.
Mr Walsh, the chief executive of BA's parent group International Airlines Group (IAG) made the comments in an article in today's Daily Mail.
The Dublin native said: "If the Government continues to dither over a new runway, then I'll move my business elsewhere. We now have airlines in Dublin and Madrid, and can expand our business there, supporting the strengthening Irish and Spanish economies."
His comments come as the British Government announced that the final decision on whether to build an additional runway at Britain's busiest airport will be postponed until at least next summer.
"This is not just fighting talk - we have the practical ability to expand elsewhere," Mr Walsh continued.
"This means Spain and Ireland will get the economic benefits and new jobs from our expansion plans, while the UK Government twiddles its thumbs and watches as the world progresses around it."
The debate over a new runway for London has been ongoing since it was first proposed for Heathrow in 2008.
Both Heathrow and Gatwick Airports lodged bids to be awarded the tender - but now the decision, which was supposed to have been announced last summer - has been postponed once again.
"I’m not knocking Gatwick — it’s a good airport and British Airways operates many flights there," Mr Walsh added.
"However, very few airlines support the proposal, and no one would move there while Heathrow remains open."
Mr Walsh has been vocal about his support for Heathrow's bid for the runway since the discussion first opened.
Along with IAG, he hit headlines earlier this year when the Irish Government agreed to sell its share in Aer Lingus to the company - making the BA carrier the largest shareholder in Ireland's national airline.