Ministers are to discuss the development of “vaccine passports” for travel on Friday, after the health secretary, Matt Hancock, urged the public to be patient about making holiday plans. If the proposal gets the go-ahead, several Whitehall departments are expected to be involved in drawing up the system, which would form the UK’s contribution to what could become a global approach to proving who has been vaccinated. A government spokesperson said: “The UK government, like most nations, wants to open up international travel in a responsible safe and fair manner and we continue to be guided by the science. “We want to ensure there is an internationally recognised approach to enable travel and are working closely with international partners to do so.” Government insiders are keen to stress that the idea is at an early stage – and there is as yet no guarantee that foreign holidays will be a possibility in 2021. They also underline the fact that any certificate to prove someone has been vaccinated would not be intended for used domestically, for allowing access to venues such as pubs and restaurants, for example. Ministers will discuss the idea at a meeting of the Covid-O committee, the key decision-making forum for day-to-day management of the pandemic. A briefing paper for the meeting, leaked to SkyNews, said: “We should not set even speculative timelines on when this may change border measures.” Hancock insisted on Thursday it was still too early to be certain about what the summer holds. His cautious message came after a week of conflicting signals on whether travel restrictions and other Covid rules will be lifted in time to allow summer travel. The health secretary had previously pointed to his hopes for a “happy and free great British summer”, but on Wednesday the transport secretary, Grant Shapps, and the prime minister urged caution. Hancock told BBC Breakfast: “I know that people are yearning for certainty over whether they can have a summer holiday, but pandemics are difficult times and there is a lot of uncertainty, so I am afraid that people will have to be patient before we can get that certainty.” In Scotland, the first minister, Nicola Sturgeon, also echoed the uncertainty. She said: “Right now, today, I would say to people not to book foreign holidays, and I would say just be cautious about booking holidays even domestically. If you want to take the chance that it will be ok, that’s not for me to decide for you … but I can’t give you 100% guarantee that by the time we get to the date things will be OK … if you want to err on side of caution then hold off a little bit.” Holidays are banned under the current lockdown, but the travel industry is desperate for rules to be relaxed by summer. As of next Monday, all arrivals from more than 30 high-risk countries will have to quarantine in hotels near their arrival airport for at least 10 days, at a cost of up to £1,750. The system appeared to be off to a shaky start on Thursday, with the booking website crashing and reports of few rooms available. According to the World Travel and Tourism Council (WTTC), the chopping and changing of rules over the last year has inflicted greater damage to the UK’s economy than has been seen in other European countries. In a statement on Thursday quoting data from Oxford Economics, it said the UK faced a GDP loss of 10% in 2020, while Germany, which imposed fewer travel barriers, would experience a loss of 5.3%. “We believe the impact of constantly shifting policies on testing, quarantines and the placing of countries in so-called high-risk red zones, will jeopardise the return of a sector which contributes nearly £200bn annually to the UK economy,” said the WTTC president and CEO, Gloria Guevara. The government is under growing pressure from its own MPs to clearly set out plans for easing restrictions once the most vulnerable citizens are vaccinated. Steve Baker, the Conservative MP and deputy chair of the Covid delivery group, urged the government not to be swayed by pessimistic public pronouncements from scientists. Several experts have sounded warnings in recent days about the risks of reopening schools and the economy too rapidly. “Having a full public debate is essential at this time but I fear senior scientists are failing to recognise their power to spread despair and despondency,” Baker said. “Some seem to be floating untested hypotheses in the media. Doing so is not science. It is the death of science. Perhaps worse, it brings scientists squarely into the political domain, something we would I am sure all like to avoid.” He said Boris Johnson must stick to the 22 February date he has given in recent statements for announcing the “roadmap” out of lockdown. That date would allow schools the promised two weeks’ notice if they are to reopen on 8 March, as Johnson has said he hopes they will. In the next 10 days, Johnson, senior ministers and scientific advisers will be weighing up the latest data on how the vaccine rollout is progressing and what impact it is having on death rates, hospitalisations and the spread of the virus.