https://www.bbc.co.uk/news/uk-politics-56605598Demanding a Covid passport as proof of a jab or test to access jobs or services is "dangerous, discriminatory and counterproductive", opponents say.
Baroness Chakrabarti warned the passports risked creating a "checkpoint Britain" as more than 70 MPs railed against their use in England.
Labour's Jeremy Corbyn and senior Tory Iain Duncan Smith are among a broad coalition who pledged their opposition.
The government said no final decision had been made on Covid passports.
But a series of Covid passport trials are being planned to test their use in different venues, the Daily Telegraph reported.
A review is taking place into whether passports could help to reopen the economy in England, with discussions also taking place across the devolved nations.
Prime Minister Boris Johnson has previously said people could be asked to provide a vaccine certificate for entry into pubs in England, saying it "may be up to individual publicans".
Certification could involve people being either vaccinated, having had a recent negative test or having previously been infected, the PM said.