Chancellor Philip Hammond said today it is possible that Britain leaving the European Union without a deal could result in no air traffic, but nobody thinks it will happen due to the "mutual self-interest" of securing an agreement.
Speaking during a hearing at the Treasury Select Committee today, Hammond said:
It is theoretically conceivable that in a no deal scenario there will be no air traffic moving between the UK and the European Union on the 29 March 2019. But I don't think anybody seriously believes that that is where we will get to.
"There is a range of outcomes and what we will need to do, at a point in time, is determine what is a realistic worst case scenario that we need to plan for and invest for," he added.
"On that specific point, it's very clear that mutual self-interest means that even if talks break down, even if there is no deal, there will be a very strong compulsion on both sides to reach agreement on an air traffic services arrangement," Hammond said.
The aviation industry has been vocal about the need for certainty when it comes to flying rights in the wake of Brexit.
All flights within the EU have been governed by the Open Skies agreement allowing any EU airline to fly between any two EU places. Once Britain leaves the bloc it would need to negotiate a new treaty to confirm flying rights.
Karen Dee, chief executive of the Airport Operators Association, said: "The chancellor is right that we will need a new legal framework the day after Brexit to ensure continuity of air services. With airlines putting tickets on sale up to 18 months in advance of the date of travel, it is vital that a transition deal is agreed as soon as possible to give consumers and businesses the confidence their future travel will be uninterrupted."
Irish airline Ryanair has previously made a similar observation to the chancellor's, saying that the UK could be left without any flights to and from the EU if Brexit negotiations did not put aviation at the centre of negotiations.
And last month, Gatwick boss Stewart Wingate said that while he was confident that aviation was a top priority for the government, time was ticking to secure certainty for flying rights, with the long lead times that airlines have on selling tickets.
“I’m very encouraged that the industry as a whole in the UK is standing shoulder to shoulder and is presenting a unified face to government, to say that what we need more than anything is certainty for the future of aviation flying rights once Brexit happens,” Wingate said.
Meanwhile, a report from a crop of the UK's biggest airports to the government has warned that uncertainty about securing a Brexit deal risked sparking a slump in air travel.