P&O Cruises has said that anyone wanting to take its cruises around the British Isles this summer will need to be vaccinated first. Travellers will have to prove that they have had two coronavirus jabs to take the trips which depart from June.

Saga Cruises and Virgin Voyages in the US have made similar moves recently. It comes amid renewed fears about the damaged travel industry, with airports warning that summer 2020 passenger numbers were their lowest since 1975.

P&O Cruises, part of the Carnival group, will run trips on two ships this summer. The Britannia will cruise from Southampton along the south coast of England for three or four days, and the Iona will travel up to Scotland from Southampton for seven-day trips.

Carnival said that passengers wishing to board would have to have had both.

Guests will also have to have travel insurance that "must include medical and repatriation cover" and medical expenses related to Covid-19. Guests and crew will be expected to respect social distancing rules and wear masks when appropriate. Should anyone test positive on board, they will be isolated and quarantined.

Paul Ludlow, the president of P&O Cruises, said: “Carnival expected a government-approved way to prove people had been vaccinated by the summer.

"This is moving at pace," he said. "We anticipate by the 27 June, which is our first sailing, there will be a government-accredited scheme to prove your vaccination, but at the very least, then of course, a letter from your GP would suffice."

He said that P&O Cruises was "in close conversation with government every day" about travellers being able to prove their vaccination status.

"At the moment we're stipulating that all guests of all ages must be vaccinated to come on board with us."

Carnival follows Saga cruises, which said in January that all customers had to be vaccinated. British Airways also plans to let people register when they have had two vaccinations on a smartphone app. The cruise industry was brought to its knees after regulators around the world stopped ships from sailing to try to limit outbreaks.

There were a number of deaths from Covid-19 after people were infected on board Carnival ships early last year. The first UK citizen to die of coronavirus was infected on the Carnival-run Diamond Princess cruise ship in Japan. At the time, the outbreak on the ship was the largest outside mainland China, with more than 600 people infected.

Simon Calder, travel editor of the Independent, said: "A lot is unusual" about the "staycation" cruises P&O is planning.

"Because the voyages are 'cruises to nowhere', the captains will look at the weather forecast and aim to sail where it is warm and sunny." He added the P&O concept is "you can look but you can't touch".

"On a voyage around the Scottish islands, for example, Iona will anchor off Iona, the magical island after which she was named, but you can't step ashore," he said, adding: “Doing this circumvents all kinds of problems.

"There are concerns about shore excursions. Some ports of call may not welcome hundreds of people from a wide range of locations wandering around, and conversely some cruise lines do not want their passengers to mingle with locals - MSC Cruises has made it a condition of travel.” Carnival has been burning through cash and last quarter said it had made a net loss of $2.2bn.

Airport operators have also been on the ropes due to the coronavirus crisis. They said that passenger numbers travelling through UK airports last summer plunged to their lowest level since 1975. Airport Operators Association chief executive Karen Dee called for tailored government support.

She said: "Despite dealing with the biggest crisis in their history, most airports remain operational to support vital public services, such as Royal Mail, air ambulances, Coastguard and the National Police Air Service, as well as other critical services such as freight, including PPE and vaccines."  The Unite union also called for tailored support, saying that more than 5,100 UK aviation and related jobs have been lost every month since February 2020.

Unite assistant general secretary for transport Diana Holland said: "It has been heart-breaking to see so many UK jobs go in aviation when we know that demand will come back.

"A staggering number of workers in the sector are now unemployed but when we look across the Channel, we see that a different approach from governments actually saves these jobs.” The government has previously said that it has provided unprecedented support to businesses across sectors of the economy including aviation.

A spokesperson said that the government was committed to restarting cruise travel when it is safe to do so, and is working closely with the sector to prepare for a safe and successful restart.

The spokesperson said: "We have put in place an unprecedented package of business support and recently extended government-backed loans and furlough payments to businesses, including in the travel industry. Around £7bn has been pledged to the aviation sector since the start of the pandemic, and through the Global Travel Taskforce we are working hard to restart international travel when it is safe to do so."