More than 70 MPs as well as peers from the House of Lords have launched a campaign claiming coronavirus vaccine passports would be “divisive and discriminatory”.
The cross-party opposition includes 40 Tories and former Labour leader Jeremy Corbyn.
A pledge has been signed by Conservative former leader Sir Iain Duncan-Smith, Labour former shadow chancellor John McDonnell and ex-Lib Dem leader Tim Farron.
It has also been backed by a string of Tory former ministers including Esther McVey, Nus Ghani, Mark Harper and Harriett Baldwin.
Former shadow attorney general Baroness Shami Chakrabarti said the scheme would be “dangerous, discriminatory and counter-productive”.
The government has insisted no final decisions have been taken on whether Covid-status certification could play a role in reopening the economy.
It comes as a report in The Daily Telegraph suggested a series of pilot tests for certificates were being planned, which could include the FA Cup final and other sporting events in May.
Boris Johnson has defended the idea and suggested a certificate could give “maximum confidence” to businesses and customers as society reopens.
Any scheme is likely to go beyond just showing whether someone has had a vaccine – as jabs are not mandatory – covering whether they have had Covid-19, and so are likely to have antibodies, or if they have a negative recent test.
Baroness Chakrabarti, the former director of human rights organisation Liberty, told BBC Radio 4’s Today programme: “It’s dangerous, it’s discriminatory, it’s counter-productive.”
The Labour peer warned that using coronavirus certificates could create a “checkpoint Britain” as she urged for the country to “open up together” as restrictions ease.
“It’s one thing to have a passport to travel internationally, that is a privilege, even a luxury, but participating in local community life is a fundamental right,” she added.
The group’s pledge has been backed by Big Brother Watch, Liberty, the Joint Council for the Welfare of Immigrants (JCWI) and Privacy International.
Senior Tory MP Sir Graham Brady, who is also a signatory to the pledge, which has been backed by a string of Conservative former ministers, insisted the aim should be to return to normal life.
The chair of the 1922 Committee of backbench Conservative MPs said: “Covid-status certification would be divisive and discriminatory.
“With high levels of vaccination protecting the vulnerable and making transmission less likely, we should aim to return to normal life, not to put permanent restrictions in place.”
Earlier this week, Labour leader Keir Starmer indicated there could be opposition to the move among the public if death rates are near zero and hospital admissions are very low.
A government spokeswoman said: “The review is considering a range of issues, including the ethical, equalities, privacy, legal and operational aspects, and what limits, if any, should be placed on organisations using certification.”
Emma McClarkin, chief executive of the British Beer and Pub Association, said that introducing vaccine passports could potentially “scupper things” for hospitality venues which are trying to reopen.
On the possible use of coronavirus certificates, she told BBC Breakfast: “This would be an additional burden put on to the pubs. We are desperate to get back open again. We are desperate to do that.
“We will play our part in test and trace but the additional burden of the vaccine passport could really, really scupper things.
“It is a difficult process for us to implement in venues and yet today we have not had a consultation with the government about how we would do this in pubs.”