Britons holidaying in Tenerife are being warned of “constant chaos” and long delays at airport passport control when they touch down.
Tourism leaders on the island have denounced the situation as an embarrassment partly caused by Brexit.
Urgent action is needed to prevent one-hour queues affecting hundreds of thousands at Tenerife South Airport, they said.
Delays had been going on “for months” following the implementation of passport control for UK visitors on the largest of Spain’s Canary Islands.
The British market continues to be the primary source of tourists with 1.4m visitors in the first nine months of this year.
Pictures on social media show friction at the border with queues for EU citizens often small or non-existent, while those for Britons snake around the terminal.
Hoteliers warn waiting times are just as bad at taxi ranks where new arrivals crowd at peak times, saying it does not match the otherwise first-class infrastructure.
Concerns have been raised by the Ashotel group, the hospitality association of Tenerife and other Canary Islands of La Palma, La Gomera and El Hierro.
Jorge Marichal, president of the Spanish Confederation of Hotels and Tourist Accommodations, said the airport “is starting to become quite tiresome”, adding it was providing a poor first impression.
He said: “This lousy image as the main gateway, both for visitors and for our own residents. We deserve a 21st century facility.”
Mr Marichal blamed decades of “neglect” in state budgets.
Ashotel vice president Victoria López said blockages occur only in passport control for passengers coming from the UK.
She said: “This collapse in control is not an extraordinary one-off situation, when the flights are scheduled and it is known well in advance when they will arrive.
“This information would allow for reinforcements of personnel if necessary.”