Travellers have been given a “false impression” about what insurers will and will not cover, the consumer group Which? has previously warned. Insurers have used confusing policy names, such as “Covid cover” or “enhanced Covid cover”, to reassure customers despite policies containing harmful exclusions, Which?’s report found.

Demand for travel insurance has risen in the past week. One company, CoverForYou, reported a 40pc rise in insurance policy sales on Sunday and Monday following changes to travel rules.

Increased uncertainty and last-minute changes to government policies will be a big blow to people’s confidence, warned Ian Bell of RSM, a consultancy. He called for more support for the struggling travel industry, such as bearing the cost of PCR tests for all inbound travellers.

Flight companies must offer a cash refund for a cancelled flight. Some airlines have kept flexible travel policies in place for all passengers, which means those who are unable to travel or choose not to could change their flight or request a voucher.

British Airways and easyJet flights can be rebooked without charge, but passengers will have to pay the difference in the fare if the new tickets are more expensive. Ryanair flights booked between Nov 20 and Dec 11 2021 will also be covered under a zero-change fee policy.

However, passengers are unlikely to receive any cash refunds for flights that are still running and they choose not to take.