TUI has scrapped all flights due to depart to mainland Spain and the Canary Islands on Sunday.
The travel company said it was “incredibly disappointed” at the short notice after the tourism industry ground to a halt during coronavirus lockdown.
Andrew Flintham, managing director of TUI UK & Ireland, said the company would contact customers to arrange refunds or rebookings.
Customers currently on holiday will be able to return on their intended flight home, he said.
Mr Flintham added: “We’re incredibly disappointed that we didn’t get more notice of this announcement, or that this decision wasn’t made yesterday, as many Brits travel on holiday at the weekend.
“We also look to understand why quarantine has been issued for a whole country, including the Canary Islands and Balearic Islands, when the travel advice isn’t aligned (only applying to mainland Spain).
“It demonstrates why clear regional travel corridors need to be considered.
“The health and safety of our customers and colleagues is always our highest priority and welcome travel advice that protects those that holiday with us.
“However, the UK Government must work closely with the travel industry as this level of uncertainty and confusion is damaging for business and disappointing for those looking forward to a well-deserved break.”
British travellers who return from Spain from midnight last night now face two weeks at home.
A Government spokesperson said: “Spain has been removed from the lists of countries from which passengers arriving in England, Scotland, Wales and Northern Ireland are exempted from the need to self-isolate.
“Protecting public health is our absolute priority and we have taken this decision to limit any potential spread to the UK.”
Brits told only go to Spain if essential & must isolate for 2 weeks when back home
And tourists have been told not to travel to the European country unless it is “essential”.
The Foreign Office warned holidaymakers against trips to mainland Spain – but the Canary Islands and the Balearic Islands are exempt from the restrictions.
The Government department website says: “From 26 July, the Foreign & Commonwealth Office (FCO) advises against all non-essential travel to mainland Spain based on the current assessment of Covid-19 risks.”