One of the most significant political controversies of the coronavirus period is likely to be over the idea of Covid “passports” – app-based, biometric certificates that would allow people entry to potentially crowded spaces. While they are sometimes referred to as “vaccine passports”, these would not just show vaccination status. Other ways people could prove they were safe to mingle would be a sufficiently recent test showing significant Covid antibodies, or a very recent negative test for the virus.

These are distinct from the idea of a proof of vaccination to be allowed to enter overseas countries, which is less contentious.

The government is still looking into the idea of Covid certificates for a range of possible activities, covering mass get-togethers such as sports events and concerts, crowded venues including theatres, cinemas and nightclubs, and even more everyday places such as pubs and many shops.

Views on the idea vary considerably – and are not entirely based on party lines.

Opposed

Conservative libertarians. Centred on the Covid Recovery Group (CRG) of Tory backbenchers, at least 40 Conservative MPs have signed up to a campaign against Covid certification, backed also by a variety of civil liberties groups.

The CRG has been pushing more generally for lockdown restrictions to be lifted sooner than planned given the speed of the UK’s vaccine rollout, and is extremely wary of most of the ideas based around Covid certificates. Graham Brady, who heads the 1922 committee of Tory backbenchers, has called certification “divisive and discriminatory”, saying the vaccination programme meant minsters should “aim to return to normal life, not put permanent restrictions in place”.

Other Tory opponents come from a longer-standing party tradition of civil liberties, such as David Davis, who in 2008 stepped down as shadow home secretary and re-stood for parliament in opposition to plans to extend detention without charge for terror suspects.

Liberal Democrats. Also firmly in the civil liberties camp, the party has pledged to oppose the measure. In a comment piece for the Daily Telegraph last week, the Lib Dem leader, Ed Davey, likened Covid certificates to ID cards, saying they were “illiberal, unworkable and would be utterly ineffective in keeping people safe from Covid”.

Labour leftwingers. Among the MPs who have signed up to the campaign against the plan are a number of Labour backbenchers from the left of the party, including Jeremy Corbyn – officially he remains an independent MP after the party whip was suspended – Rebecca Long-Bailey and Clive Lewis. Lewis said there were a number of others on the Labour side who had misgivings.

It is worth noting that for all of these opponents, the main issue appears to be a formal scheme, like a biometric ID card. It is possible that some or all of the MPs from the various parties could be more amenable to systems such as obliging people going to a mass sports event to take a Covid test before they go in, as a one-off condition.

Opposed – but less vehemently

Labour frontbench. Keir Starmer laid the groundwork for this by saying in an interview with the Covid certificate-wary Daily Telegraph that he believed the “British instinct” was against the idea, even though party officials briefed that he was not ruling the idea out.

Overnight into Tuesday, the party indicated this opposition was now firming up. It is, however, not definitive, and depends in part on what any final scheme proposes. Jonathan Ashworth, the shadow health secretary, said on Tuesday that while he could see the logic for tests before entry to the likes of football games, he would oppose an ID card-style system. Ashworth said: “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, on an app.”

While this sounds similar to the view of the Labour MPs who backed the civil liberties groups’ campaign, the Labour leadership view does hold open the possibility of a bit more flexibility, and much will depend on what is eventually proposed.

Supportive if sceptical

Scientists. While the government will be relying heavily on its official scientific advice, ministers will be buoyed by some backing from other parts of the scientific community – albeit with caveats.

A report by the Royal Society in February concluded that even purely vaccination-based certificates were feasible but would need significant safeguards, both against possible discrimination and to ensure they were not seen as indefinite, given the fact immunity levels could wane.

However, some scientists have warned about the protection levels offered by entry restrictions, for example to sports events, being governed by rapid lateral flow tests, given the relatively high proportion of false negative results.

Business groups. Reaction overall has been mixed, with some pub groups wary about the idea of having to enforce entry based on certificates. The CBI has broadly welcomed the idea while stressing it must happen in an inclusive and consensual way.

Supportive (it seems)

The government. Boris Johnson has been surprisingly bullish about the general idea, even suggesting that it could be up to individual pubs to decide what sort of health certification would be required for entry. Amid the looming row, the Cabinet Office minister, Michael Gove, has been holding meetings with wary MPs, part of a charm offensive as the review took place.

The review document into Covid certificates and other lockdown-easing measures published on Monday holds open the possibility of them being used for a wide variety of events and businesses. It rules out their use only for key public services, public transport and “essential shops” – thus leaving it theoretically possible that they could be required in most shops and in hospitality venues.

What is eventually recommended will depend on factors including scientific advice, the progress of the vaccination programme, and on Covid infection rates – but also, crucially, whether ministers believe any plan would pass the Commons. Ministers have indicated that a parliamentary vote would happen, but this is not completely confirmed.

Also a factor – parties in Scotland, Wales and Northern Ireland

The review into certification has been a UK-wide one, and ministers hope any policy would be the same across the country. However, health is a devolved matter, and to avoid different rules in different parts of the UK, Westminster ministers will need to keep leaders elsewhere onside. Nicola Sturgeon has confirmed that Scotland is not averse to the idea being tried out.