One of the companies involved in the Covid-19 vaccine passport has said that the system could be "redeployed" as a national ID card, amid concerns over “mission creep”.

As Boris Johnson urged nightclubs and venues with large crowds to adopt Covid-19 certification as a condition of entry, MPs and campaigners warned that the system was “intrusive” and raised the possibility of discrimination.

Concerns were raised that people will be forced to share sensitive information to participate in normal, everday life, particularly as the Government has reserved "the right to mandate certification” at a later date.

Fears have been fuelled by the fact that the £250,000 contract to provide the cloud software for the certification system was handed to Entrust, an American IT firm which has previously been involved in rolling out national ID systems in Albania, Ghana and Malaysia.

In a blog written shortly before it was awarded the contract, Jenn Markey, product marketing director, Entrust, commented that “vaccine credentials can become part of the infrastructure of the new normal”.

She said: “With the infrastructure and investment necessary to ensure a viable vaccine passport, why not redeploy this effort into a national citizen ID program that can be used for multiple purposes, including the secure delivery of government services, secure cross-border travel, and documentation of vaccination.”

In the UK, controversial identity card plans were scrapped by the coalition government in 2011 after outcry over the intrusive nature of the scheme and its impact on human rights, including from Mr Johnson who said he would "eat" a card if required to produce it.

However, it is feared that the draconian requirements to prove health status will allow “mission creep” into other requirements, according to Silkie Carlo, director of Big Brother Watch.

Security experts warned that in order for the passport to be linked to an individual and avoid fraud they would also have to show identification.

“This is a giant leap towards ID cards,” Ms Carlo said, adding that if the “Government goes ahead with mandated Covid passes it is likely we will look to bring legal challenges."

The findings of a Cabinet Office review also said the passes could allow businesses to stay open “if the country is facing a difficult situation in autumn or winter”, suggesting they may be utilised in any future lockdowns.

Pubs and nightclubs on Tuesday night said they would refuse to introduce the system, as leaked modelling suggested it would only allow them to reach 71 per cent of their pre-pandemic turnover, a loss of £3.5 billion.

But the possibility has been raised that the use could be widened out to other sectors, with the Cabinet Office review saying a ban on other companies requiring certification would "be an unjustified intrusion" on how they keep their premises safe.

Government commissioned research on the vaccine pass, seen by The Telegraph, also shows that focus groups were asked about the possibility of them being used for weddings, funerals and work events.

In the December focus group conducted by Zühlke Engineering, a Swiss company involved in the contract tracing app which has staff working within the Department of Health, participants were also asked about it being used for builders attending their home.

Vaccine passports in other countries

Tory civil rights champion David Davis, a former cabinet minister, told The Telegraph that domestic Covid passports are “a very bad idea”, “intrusive” and “completely out of the tradition of Britain”.

Pointing out there were 9,000 data leaks last year from government records, he said: “There are very serious civil liberties issues, serious issues of practicality, and serious issues of discrimination."

The Government has denied any suggestion that the pass will be used as a national ID system.

It comes as a poll released on Tuesday showed a third of adults aged 18-34 had deleted the NHS Covid-19 app from their smartphones, with more intending to remove it after “Freedom Day” on July 19.

Overall, less than half of adults have the app installed, Savanta ComRes found.