Passengers have been left stranded and hundreds of jobs are at risk following the collapse of one of Britain’s largest regional airlines.

Government officials have been forced to scramble contingency plans after Stobart Air, which operates services for Aer Lingus, British Airways and KLM, stopped trading and called in liquidators.

Almost 500 jobs are thought to be at risk, while thousands of passengers could be stranded following a string of cancellations.

In a statement Aer Lingus said Stobart Air had notified it late on Friday night that it was ceasing operations with immediate effect.

Of the 12 routes affected, Aer Lingus will operate five, while BA City Flyer will operate two. Plans are still being determined for the remaining routes.

The collapse comes amid rising anger among airlines about the government’s approach to reopening international travels.

Bosses reacted with fury after ministers chose to remove Portugal from the travel green list. It had been one of just a handful of holiday destinations open for quarantine-free travel.

Paul Charles, chief executive of travel consultancy The PC Agency, accused the government of “strangling aviation”.

“The majority of UK adults have received both vaccine doses and should be given the freedom to fly,” he told the Telegraph.

Stobart Air was part of London-listed Esken, the aviation and energy business formerly known as Stobart Group.

It operated a string of Aer Lingus regional services, as well as BA City Flyer services from London City Airport and KLM Cityhopper from Amsterdam.

In April Esken struck a deal to sell Stobart Air for a nominal £2 to Ettyl, a startup led by 26-year-old Isle of Man Bitcoin investor Jason Scales.

But the rescue deal collapsed and police have been called in to investigate potential irregularities related to the transaction.