Speaking on BBC Breakfast on Monday (22 March), Hays Travel chair Irene Hays said vaccination levels in popular destinations would be a clincher for the UK government.
"I think to travel abroad, yes, definitely – the government will be looking at the infection rates and the progress of vaccines in other countries," said Hays.
"My opinion is it will be nuanced; that some places will open and they will have requirements for some sort of certification or perhaps some lateral flow test on entry, but at the minute, as usual, it’s not a clear picture."
She said it was also unclear whether the UK would be part of the EU’s digital green certificate. "That position’s not clear in the UK yet, but that would be a very good thing to demonstrate that you do have vaccinations."
Hays was speaking amid a chorus of "don’t book" messages. The latest came on Monday morning from health minister Helen Whately, who told the programme: "My advice would be to hold off on booking international travel… it feels premature to be booking international holidays at the moment."
Whately was asked if 17 May was now unlikely to be the date when Britons could start travelling, it being the current "at the very earliest" date set by prime minister Boris Johnson last month.
She declined to speculate, but said: "As anyone can see, there are rising rates of infection in Europe. With that there is increasing risk of variants. So I would say to people, just hold off."
Calum Semple, a professor of outbreak medicine, was asked why older travellers who had had both vaccine shots could not travel.
He said: "You’ve still got a lot of people that aren’t vaccinated. People will bring the virus back into the community, potentially bring back resistant strains.
"We have to think of the good of the whole nation. Until prevalence is low in other countries, we really don’t want viruses being brought into this country."
Semple added: "The issue here is there is really high prevalence of the virus in Europe, so although Britain has essentially got its house in order with quite stiff lockdowns and brilliant roll-out of the vaccine, sadly, in European countries, we’re seeing a third wave at the moment and there’s no reason to expect that to go down until they get lots of non-pharmaceutical interventions."
However, Arancha Gonzalez Laya, Spain’s foreign minister, said Spain’s "non-stop" vaccination programme would help it prepare for the summer.
"Of course, this will not be a summer like the ones we’ve known in the past," she said. "But I’m sure if we proceed with vaccination, we will be able to spend a bit more time outside our countries.
"I think the summer will look a little bit better than last summer. I am sure with this [that] the summer will be brighter and we will be more than glad to receive tourists from the UK."
Cyprus also used the programme to underline plans to welcome vaccinated tourists from May. Philokypros Roussounides, director general of the Cyprus Hotel Association, said this plan "still stands". "We had a spike in bookings once we announced the vaccine permission," he said.
Cyprus, with less than a million people, hoped to have 60-70% of its population vaccinated by "mid-end June", he added. "The UK is the biggest market for us. We missed them so much last year and we hope that doesn’t happen again this year."
Latest Hays Travel booking figures show 31% of holidays sold since 1 March are for 2021, with the remainder for 2022.
Hays said European travel was "still very, very uncertain", but destinations like the Caribbean, Seychelles and Maldives were opening to long-haul travellers.
Domestically, she said capacity was tight, but "seacations" on cruise ships were providing new opportunities. These include P&O Cruises, Cunard, Princess Cruises, MSC Cruises, Fred Olsen and Viking.