Balpa has carried out its own analysis of data published by the Department for Transport to support its last traffic light review on 24 June and found “significant gaps in the data and large amounts of suppressed information”.

“The majority of the data fields are blank, containing no or supressed information, and even the incomplete data sets only cover countries on the red or green lists,” found the union.

“No data published at all on well over 200 countries and territories currently on the amber list, preventing the travel industry on planning ahead.”

The travel industry has criticised the government for a lack of clarity and data when making decisions on a country’s traffic light status, particularly over the decision last month to suddenly move Portugal from the green to amber list with only a few days’ notice.

Balpa’s acting general secretary Brian Strutton added: “Not enabling safe travel to low-risk countries will mean more redundancies for pilots and others in the travel sector, on top of the thousands that have already taken place.

“Pilots would expect a government that claims to understand the impact of restrictions on aviation to carry out thorough assessments of all of the major UK travel routes and destinations, so that restrictions can be lifted as soon as possible.

“If decisions are to be trusted, all of the evidence that they are purported to be based on must be published and a detailed explanation provided on the huge holes and hidden figures in the data.”

The Department for Transport has been approached for comment on Balpa’s criticism and are awaiting a response.