Changes to travel quarantine rules covering Spain are "yet another blow" to British holidaymakers - who will see their plans thrown into "chaos", British Airways has said.

In a statement, the airline said its flights were continuing to operate, but it was "disappointed" the Government was now advising against all but essential travel to mainland Spain and re-introducing a two-week self-isolation requirement on those returning from the southern European country.

It said the move was "throwing thousands of Britons' travel plans into chaos", adding: "This is sadly yet another blow for British holidaymakers and cannot fail to have an impact on an already troubled aviation industry."

Following the Government's announcement on Saturday, the UK's biggest tour operator Tui said it had cancelled all flights due to depart to mainland Spain and the Canary Islands on Sunday Andrew Flintham, managing director of TUI UK & Ireland, said: "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."

He said the company was looking to understand why the quarantine rule applies to people returning from the whole of Spain, while current Foreign and Commonwealth Office (FCO) advice against all but essential travel only applies to the mainland.

Mr Flintham added: "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."

Another airline, easyJet, also expressed its disappointment that the Government had shut down the travel corridor with Spain because "the increased occurrence of coronavirus is regional rather than nationwide".

In a statement, easyJet said it planned to operate a full schedule "in the coming days", adding that customers no longer wishing to travel could seek to transfer their flights without a fee or receive a voucher.

Airlines UK, the industry association representing UK-registered carriers, said in a statement that "public health must be the priority" but that the Government's change showed "why regional travel corridors need to be considered, so that travel to safe parts of a red country can continue".

It added: "We also need to see the introduction of testing at UK airports so that those who are Covid negative can continue to travel without the need to self-isolate upon arrival."

A spokesperson for the Association of British Travel Agents (Abta) said Spain was British holidaymakers' "most popular destination", attracting over 18 million visitors each year Commenting to the Government's "disappointing" quarantine rule change, they added: "Abta has said consistently that protecting public health must be the priority at this time, and it is vital to base decisions about travel on the best health and scientific advice.

"We suggest the Government considers lifting the quarantine rules for flights to and from certain regions with lower infection rates, or to places such as the Balearic Islands or The Canaries - which are geographically distinct from mainland Spain - to avoid further damage to the UK inbound and outbound tourism industries."

Rory Boland, editor of consumer magazine Which? Travel, said: "Many holidaymakers will be deeply angry that the Government didn't make this decision 48 hours ago, before tens of thousands of them flew off for their summer holidays in Spain.

"Many would not have travelled if they had known they'd face 14 days of quarantine on their return."

He called on the Government to give " urgent clarity" in its travel advice covering travel to Spain "as this will have a more serious impact and may require tour operators to bring holidaymakers home early at a time when they are already under huge financial strain".

Mr Boland warned: "For those with future bookings to Spain, many tour operators are now likely to cancel holidays."