Ryanair boss Michael O’Leary has put his flights where his mouth is, slashing the budget airline’s planned growth in the UK from 12% to just 5% to expand in Italy and Germany instead, months after warning that a vote to leave the EU would be “absolutely crazy”.

Uncertainty over Brexit in the UK — which accounts for just over a quarter of Ryanair’s business — “will continue to overhang our business,” O’Leary said.

He threatened the Government that if the UK quits Europe’s Open Skies system, “we will continue to adapt to changing circumstances in the best interests of our customers, people and shareholders.”

Despite the Brexit hit, Ryanair flew a more positive path than struggling rival airlines, raising its long-term growth forecast by 10%, and saying it will fly 200 million passengers per year by 2024 — up from 180 million — and predicting it will command more than a fifth of Europe’s short-haul market.

Post-tax profit for the crucial summer six months to October rose 7% to €1.2 billion (£1.1 billion).

O’Leary added that floundering airlines giving up routes to save cash meant Ryanair will be moving into more airports passengers have heard of: “We have EU incumbents retrenching, restructuring… creating more and more opportunities for Ryanair, particularly in primary airports,” he said.