It would be “remiss” of the government not to consider Covid certification as a way of fully reopening the economy, Vaccines Minister Nadhim Zahawi says.
Amid criticism of the plans, Mr Zahawi said: “It’s only right that we look at all these options that are available to us to take our lives back.”
The government said certificates showing vaccination, test or immunity status could “provide reassurance”.
Speaking on Monday, PM Boris Johnson did not rule out the idea.
But many MPs have criticised the plans, with senior Tory backbencher Mark Harper calling for a vote on the issue.
Mr Zahawi was keen to point out that the concept of using Covid certificates to allow international travel was distinct from a review of using them within the UK.
“But I think it would be remiss and irresponsible for us to not look at all these things,”, adding that any certificate would show test results as testing is available to all, unlike vaccines.
But he stressed they would not be needed for the reopening of outdoor hospitality or non-essential retail on 12 April or indoor hospitality from 17 May.
And after government scientific advisers warned indoor mixing was “highly likely” to lead to a resurgence in hospitalisations and deaths, Mr Zahawi said this was why England’s roadmap out of lockdown was spaced at five-week intervals.
The UK government said it was working with the devolved administrations in Scotland, Wales and Northern Ireland to seek a “consistent approach”.
Mr Johnson has the power to set public health regulations for England, but it is a devolved power in the other UK nations.
A government review is currently being carried out to see how certificates that show testing status could work in England – and they are going to be trialled at upcoming events including the FA Cup final at Wembley Stadium.
No decision has yet been made on whether Covid status certificates will be introduced, but the government has now published an update on its review.
It said they could play a role in allowing people to return to theatres, nightclubs and mass events like festivals, and could allow social distancing to be relaxed in hospitality venues.
“Even without government intervention, Covid status certification is likely to become a feature of our lives until the threat from the pandemic recedes,” it added.
A recent opinion poll of more than 8,000 UK adults suggested there was strong public support for the use of “vaccine passports” in certain situations.
More than three-quarters (78%) of those surveyed by Ipsos Mori supported their use for international travel and to visit a relative in a care home.
The research also showed 74% of people supported their use to visit relatives in hospital and 68% to attend the theatre or indoor concerts.
But opposition to Covid passports being used within the UK has mounted – with a group of more than 70 cross-party MPs criticising the plan last week.
They said demanding medical proof in order to take part in local community life, for example going to venues like pubs, is discriminatory and divisive.
Mark Harper, who chairs the Covid Recovery Group of Conservative MPs which is against lockdown restrictions, said it was not acceptable for the end of social-distancing to depend on passports.
He said the government “should ask Parliament to give its approval as ministers have promised” and that it was “crucial” that MPs are allowed to vote on the issue.
“Trying to introduce these domestic vaccine passports by the back door by linking them to removing social distancing rules just won’t be acceptable either,” he said, adding certificates could “lead to a two-tier Britain”.
Labour’s shadow health secretary Jonathan Ashworth did not rule out voting for the policy in Parliament, but said he would not support certificates for everyday activities.
“I’m not going to support a policy that – here in my Leicester constituency – if someone wants to go into Next or H&M they have to produce a vaccination certificate on their phone.”
The government has said certificates to permit access to essential public services, public transport and essential shops should “never be required, in order to ensure access for all”.
Mr Zahawi said MPs would “absolutely” be offered a vote on Covid certification, adding that “if we come to a decision on this of course it will come to Parliament”.