Speaking at the Capa Acte Global Summit in Amsterdam last week during a panel debate, CityJet executive chairman Patrick Byrne said negotiations had the potential to cause chaos for the European aviation industry.

He also asked why, unlike votes that have taken place in other countries that did not go the EU’s way meaning the vote was held again, the British have not been urged to return to the polls.

Byrne said: “I don’t want to be a scaremonger here but I have to say I am concerned.

“The genie is now out of the bottle and I have to ask why is there no pressure to go again and to have another vote. It’s almost as if there’s relief [in the EU] the decision has happened.

“There are people that would benefit from it.”

He said the benefits would be most likely felt by rival legacy airlines that could go on a acquisition spree while major UK low-cost carriers (LCCs) like easyJet would find their wings clipped.

Meanwhile, Lufthansa vice-president EU affairs Regula Dettling-Ott, said all three of the Switzerland’ carriers had been integrated into their EU rivals as the country remains outside of the union.

She also dismissed the possibility of the UK taking a Swiss deal, arguing Switzerland was much smaller than the UK while the deal was stacked in the EU’s favour.

Nor did the prospect of a Norwegian deal, seeing the UK remaining in the European Economic Area, curry favour with the panel.

Instead they urged negotiators not to use the industry as a negotiating pawn, with bmi regional chief commercial officer Jochen Schnadt saying: “Anything short of the status quo would be an unmitigated disaster for the industry.”

They also agreed the best thing would be for the UK to have a change of heart and reverse its decision to go.

Byrne said: “Theresa May is a very formidable lady. I think she is leading the troops up the hill to show them the abyss on the other side.

“I’m praying… we don’t have to go through this appalling nightmare.”