Tourists warned: There's no compensation if flights grounded post-Brexit
Holidaymakers are being told they will not receive compensation if flights are grounded after Brexit.
Tour operator Thomas Cook has tightened its terms and conditions as it is selling holidays taking place after the UK is set to leave the EU in March 2019.
The firm recently inserted a clause stating that it will not be liable to pay compensation or reimburse expenses for delays caused by "airspace closures".
Chancellor Philip Hammond warned on Wednesday that if the UK and the EU are unable to reach a deal over Brexit then it is "theoretically conceivable" that flights will be halted.
A Thomas Cook spokesman said: "We are selling holidays for the post-Brexit world, so we are preparing the business to operate in that environment.
"We do expect some form of agreement on aviation but we now need urgent clarity from government."
Under EU rules passengers are entitled to compensation worth up to 600 euro (£541) and reimbursement of accommodation, food and mobile phone bills when flights are delayed or cancelled.
But airlines can avoid paying out if disruption is due to "extraordinary circumstances", such as bad weather or political instability.
Thomas Cook would still offer refunds if holidays are cancelled due to post-Brexit flight restrictions.
The firm is already selling long-haul packages for post-March 2019, with short-haul trips going on sale in the coming weeks.
Many travellers book holidays far in advance to benefit from early booking deals and the best availability.
The single market for aviation, created in the 1990s, means there are no commercial restrictions for airlines flying within the EU.
Ryanair chief executive Michael O'Leary has insisted that airline traffic between the UK and the EU will stop if no agreement on aviation is reached by September next year, as schedules are planned several months in advance.