Tui and easyJet customers in tier 4 areas due to travel in the next fortnight have been given the option to take a refund or rebook an alternative holiday.
On Sunday, EasyJet said it planned to run its schedule as normal, although a range of travel bans were subsequently introduced on UK travellers.
Tui has cancelled all flights from Luton airport until December 30 following the introduction of strict restrictions for London and much of the south east of England.
The tier 4 restrictions were introduced at midnight on Saturday and include a ban on international travel unless for essential purposes.
Luton and Heathrow airports fall within the tier 4 area, but Gatwick remains in tier 2, as does Uttlesford, the part of Essex which includes Stansted.
In a statement, Tui said: “Following the UK government’s decision to introduce new restrictions for tier 4 in England we will be cancelling our flights departing from Luton airport from 20th- 30th December.
“We will be in direct contact with these customers to offer them a full refund or the option to amend their booking.”
The statement added: “Any customers that live in tier 4 and are due to depart in the next 14 days will be entitled to cancel and receive a full refund or amend for free to any holiday that’s currently on sale.
“Customers with a holiday that is due to depart in the next 14 days and is no longer able to operate will be contacted by a member of our team and will receive a full refund or the option to amend for free to any holiday that’s currently on sale.”
EasyJet said: “EasyJet plans to fly its current schedule over the coming days, however, following the UK government’s announcement implementing tier 4 restrictions which includes advice against travelling abroad, we understand some customers may now need to change their flights.
“Impacted customers in tier 4 areas have the option of transferring to an alternative flight free of charge, receiving a voucher or receiving a refund. This policy applies to any flights up until 30 December.
“All other customers can make changes to their booking without incurring a change fee up to 14 days before departure online via Manage Bookings at easyJet.com.”
An easyJet holidays spokesperson added: “We’re aware of the announcement on the introduction of tier 4, which includes a restriction on overseas travel.
“Last night we contacted customers due to travel in December. We’re giving customers impacted by the introduction of tier 4 the choice of cancelling for a full refund or to amend their holiday without incurring any fees.”