Ryanair and Manchester Airports Group will call for more transparency over how Whitehall decides which countries are on which list.
Aviation chiefs are launching a legal challenge over restrictions on international travel, the PA news agency understands.
Ryanair and Manchester Airports Group (MAG) – which owns Manchester, Stansted and East Midlands airports – will call for more transparency over how Whitehall decides which countries are on the green, amber and red lists.
This comes as the Government confirmed it is considering plans for vaccines to play a role in opening up international travel.
The quarantine and coronavirus testing requirements people face when returning to the UK are based on a traffic light system.
Before the system was introduced, the Department for Transport said assessments would be based on a range of factors, including the proportion of a population that had been vaccinated, rates of infection, emerging new variants, and access to reliable scientific data and genomic sequencing.
But the movement of Portugal from green to amber led to accusations that decisions are being based on political rather than public health motives.
There are no major viable tourist destinations on the quarantine-free green list, with the most popular countries in the amber tier.
People returning to the UK from an amber country must self-isolate at home for 10 days, take a pre-departure test and two post-arrival tests.
Ryanair boss Michael O’Leary said: “The UK’s traffic light system has been a complete shambles from the beginning.
“This go-stop-go-stop policy is causing untold damage to the aviation industry and frustrating and upsetting millions of British families when they see their holiday plans and family visits disrupted by the Government’s mismanagement of international travel.
“We call on Prime Minister Boris Johnson to explain the scientific basis behind this system that the Government seem to make up as they go along, and to establish a data-driven transparent model that could restore confidence in air travel ahead of the very crucial peak summer months.”
PA understands that several major UK airlines will support the action, in which Health Secretary Matt Hancock and Transport Secretary Grant Shapps will be named as the defendants.
MAG chief executive Charlie Cornish said the travel sector recognises “the critical importance” of protecting public health, but added the Government appears to be “unwilling to open up international travel by putting low-risk countries on the green list”.
He went on: “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.”
A Government spokeswoman confirmed work has begun to “consider the role of vaccinations” for inbound travel.
The Daily Telegraph reported that officials are analysing whether travellers who have had both coronavirus vaccine doses could avoid having to quarantine when they return from amber countries.
This could mean the return of holidays to popular summer hotspots such as Spain, Portugal, France and Italy, which are all currently on the amber list.