Ryanair and Manchester Airports Group have joined forces to mount a legal challenge against the government over its travel traffic light system.
They are demanding more transparency about how the government decides which countries qualify for the green list of safe places to visit amid the pandemic at each of the three-week reviews.
Other major UK airlines are expected to back the judicial review action.
They are demanding a swift response ahead of the start of the key summer peak for holidays.
The case will probably be heard early next week, according to Ryanair group chief executive Michael O’Leary.
The move came as Jet2.com and Jet2holidays and MAG criticised ministers for failing to place the Balearics on the green list at a time when German holidaymakers are flooding to the islands.
Jet2 chief executive Steve Heapy said: “When you take the UK government’s own criteria for deciding where holidaymakers can travel to, and apply it to the Balearics, we are left bewildered as to why we cannot fly there.”
MAG chief executive Charlie Cornish said EU countries were taking a more positive approach to resuming international travel.
“Hundreds of thousands of people from places like Germany are travelling freely and safely to low-risk holiday destinations,” he said.
The move by Ryanair and MAG to sue the government over the lack of transparency over how countries are classified in the traffic light system follows O’Leary attacking the UK’s Covid travel response as a “shambles”.
And he told the Telegraph: “[We are] trying to force the government to at least either a) be more transparent [over the traffic light system], b) publish what exactly the thresholds are at which international travel … will be allowed to restart. Or c) get some injunctive relief against the government generally on the back of vaccines that says the longer lockdown is restricting people’s freedom of movement.
“The UK has done remarkably well on vaccine rollout compared to the Europeans. But the Europeans have a much better and well-thought-out air travel and tourism recovery from the first of July for vaccinated people. And I think [the UK] is going to be embarrassed by the Europeans.”
Cornish, whose company run Manchester, Stansted and East Midlands airports, added: “The government is not being open and we simply cannot understand how it is making decisions that are fundamental to our ability to plan, and to giving customers the confidence to book travel ahead.
“These issues must be resolved urgently – and ahead of the review point later this month – to allow everyone to understand how the system operates, and to create the opportunity for international travel to resume to the fullest extent possible over the summer.”
Anger has been stoked by the government removing Portugal from the green ‘safe’ travel list with just four days’ notice at the start of the month, leaving just Gibraltar, Israel and Iceland as the only viable holiday destinations to visit without the need to quarantine on return to the UK.
A government spokesperson told the BBC: “We recognise this is a challenging period for the sector, as we seek to balance the timely reopening of international travel while safeguarding public health and protecting the vaccine rollout.
“We have provided £7 billion to help support for the industry during the pandemic.”
The spokesperson added that the government could not comment on legal proceedings.