Hospitals in tourism hotspots could struggle to cope with extra demand from holidaymakers as they try to juggle a huge backlog of patients and recover from the Covid crisis, NHS leaders have warned.

Across the country, the health service is trying to tackle waiting lists that have built up during the pandemic, while a spike in cases of the Indian variant is also causing concern.

But, as many opt for staycations this half-term and summer because of restrictions on travelling abroad, NHS Providers, which represents hospitals, warned health trusts in popular destinations were “really nervous” about the impact of an influx of tourists.

Chris Hopson, the chief executive of NHS Providers, told The Independent that trusts and ministers had to work together to ensure “we are in the best position possible to treat anybody who needs NHS care. We know, given where we are at the moment, this is going to be a struggle, given those holiday hotspots in particular.”

The problem could affect areas from Norfolk to the Lake District to Cornwall this summer, he suggested.

He also called for the issue to be considered as part of the government’s calculations around 21 June, when more lockdown restrictions are due to be eased.

Hospitals were currently “going full pelt” to try to clear waiting lists, he said.

At the same time many were seeing a rush of patients who had tried to manage their conditions themselves during the pandemic, but now needed often complex care.

This had left them under pressure even if they were yet to see many cases of the highly transmissible coronavirus variant first identified in India, he said.

“[The] current degree of pressure on hospitals is worrying especially since we saw clear summer demand surges in the two years before Covid-19,” he told BBC Breakfast.

One trust chief on the south coast had warned him they would “struggle” to meet the “significant extra demand” over the summer, he said.

Ministers had a “difficult decision to make” for 21 June, he added.

Mr Hopson also pointed to the South Western Ambulance Service, which covers an area from Cornwall to Gloucestershire, which declared a critical incident because of “extreme pressures” on its services over the bank holiday weekend.

Patients were warned they may have to wait longer for an ambulance or seek alternative medical treatment yesterday.

Mr Hopson said there were “lots and lots of extra people in the southwest, taking advantage of the bank holiday”.

“When systems come under pressure, it’s not just hospitals but it can also be ambulance services [that are affected],” he added.

Nearly 400,000 people were predicted to travel to Cornwall for the long weekend, which is also the start of the May half-term.

But pressures could be more acute this summer as millions take their annual holiday in the UK, rather than travel abroad.

Covid restrictions mean only a tiny number of destinations are on the so-called “green list” of countries UK tourists can visit without having to self-isolate on their return.

Travellers have also been deterred by last year’s chaos, when the list of “safe” travel countries was changed sometimes with just a few days’ notice.

Boris Johnson is facing increasing calls from experts to delay his 21 June plans to lift the final stage of lockdown.

Linda Bauld, professor of public health at the University of Edinburgh, today described the date as “too early” and warned it could lead to deaths that were otherwise preventable.

Last week the prime minister appeared to admit his plans now hang in the balance.

He said he “didn’t see anything currently in the data” to derail the June reopening, but added “but we may need to wait”.