A third of UK seasonal jobs in ski resorts and summer activity holidays have disappeared because of fears over Brexit, research shows.

A year after the industry warned that 25,000 jobs were at risk, a survey of 65 independent travel specialists including Mark Warner, Ski World and festive operators in Lapland revealed that a third – 1,700 among those polled – had already gone. Industry leaders have said their business models are not sustainable outside the EU because companies will no longer be able to hire and deploy British staff on temporary contracts post Brexit.

“What came back in the survey was that a large number of owners are actually looking to sell, they say ‘we are contemplating shutting down’ or ‘we will just close down because it is not viable’,” said Charles Owen, the co-founder of Seasonal Business in Travel (SBIT), which commissioned the survey.

He runs Jack’s bar in the Meribel ski resort in the French Alps and says owners are “terrified” of a post-Brexit future. Many are looking at closing down, he says, threatening a £16bn contribution to Britain’s economy, £1bn of which goes directly to the Exchequer in tax receipts.

The figures come a year after SBIT warned that Alpine resort holidays were being jeopardised by Brexit and the end of what is known as “posted worker” rules, which allow any citizen of one member state to work in another for up to two years but continue employment as a worker paying tax in their home country.

This has allowed specialist holiday operators in the Alps and elsewhere to mushroom as they typically use British staff for every stage of the package from the meet and greet and airport transfers, to child minding and cooking and cleaning services.

“Everybody thinks freedom of movement is just about Polish plumbers and painters coming to England, but it’s not, it’s also about UK nationals being able to go to Europe and work a season in a ski resort or on a summer activity holiday,” said Owen. “There are about 25,000 workers in our sector and almost all of them are British.”

Brexit will also affect others outside the travel sector who work in the EU on short-term contracts but remain on British books paying tax and national insurance contributions as if they were living in the UK.

The IT sector across Europe also typically employs people on short-term contracts.

The latest EU data shows that 49,496 British nationals are “posted workers”, issued with the A1 tax certificate which logs their contributions in their home state.

Owen says he has a break clause in his contract to run Jack’s pub that will allow him to stop operating if the posted worker arrangements expire because of Brexit.

Dan Fox, the managing director of Ski Weekends, said the EU had “brought us the most incredible benefits of freedom of movement of our staff, transport and resources”, and holidaymakers had benefited because of the explosion in small companies able to offer a diverse range of holidays.