Most Britons support the idea of vaccine passports, according to a new poll - with 62% saying they would be fine with using one to get into a pub or restaurant.
Ministers are studying their potential use, which could see access to venues granted only if customers have been vaccinated, received negative tests, or developed antibodies through past infection.
But the idea has proved controversial, with critics dismissing it as an assault on civil liberties and a potential cause of discrimination.
A survey by Ipsos MORI of more than 8,300 people aged over 16 in the UK found 78% were in favour of vaccine passports to travel abroad or to visit a relative living in a care home.
Support was also high for using the document to see a loved one in hospital (74%), or to go to the theatre or an indoor concert (68%), and for gym use or leisure centre use (63%).
Around 61% of those who responded also backed their use to attend open-air music concerts and sports events, while 58% said they would accept having to use them on public transport.
There were also high levels of support for vaccine passports being a requirement for certain jobs, such as frontline healthcare or care for the elderly and disabled.
However, when it came to balancing the potential benefits of vaccine passports to the economy against any ethical or legal concerns, the picture varied according to age and ethnicity.
Watch: 'British instinct' against vaccine passports for pub, says Labour leader Sir Keir Starmer
Older respondents and white people were most likely to believe that the benefits outweighed the concerns, while young people and those from ethnic minorities were most likely to believe the opposite.
The survey comes as hospitality and retail bosses warned vaccine passports or certification could pose a problem for frontline staff.
Kate Nicholls, chief executive of trade body UKHospitality, told a webinar on Wednesday hosted by the Confederation of British Industry (CBI): "This is quite a challenging issue for a lot of people to wrestle with.
"If you are in a consumer environment, you have legal concerns regarding age, ethnicity, gender, and I don't think considering a valid test alongside a vaccine certificate is enough.
"From a consumer position, you will also have issues regarding frontline staff having to enforce the law about this."
Boris Johnson has said "there is going to be a role" for COVID vaccine certification but suggested it might only be implemented once every adult in the UK has been offered a vaccine by the end of July.
The prime minister said last week "all sorts of things are being considered", but added it was "a bit premature" to speculate on whether pubs could ditch social distancing and mask-wearing requirements entirely by implementing a certification scheme.
"What we want to do is roll out the vaccine programme and see what that builds in terms of general resistance to the virus," he said, as he was asked about what's been dubbed a "papers for the pub" scheme.
"I do think there is going to be a role for certification," he added.
Michael Gove, the Chancellor of the Duchy of Lancaster, is conducting a review into the use of COVID certification, which is due to report back before the fourth stage of easing lockdown restrictions on 21 June.
The government is expected to give an update before then in early April.
Meanwhile, the EU is working on a digital vaccine certificate scheme that would make it quicker for people to travel through the continent.
It is expected to launch by June at the latest.
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