A 'time limit' of less than a year could be imposed on the vaccine passport scheme to head off a Tory revolt on the issue, the Mail can reveal.
Boris Johnson will give the green light on Monday to the development of a system of 'vaccine certification' as he looks to reinvigorate the economy.
Ministers believe the scheme may be essential in reopening venues such as theatres and stadiums which rely on large crowds.
But the idea of creating a new 'Checkpoint Britain' has led to a fierce cross-party backlash, with 72 MPs yesterday signing a pledge to oppose the 'divisive and discriminatory' scheme.
There was also a huge outcry over the plans yesterday, with a litany of critics branding the idea as oppressive.
The policy was even criticised by a Government adviser, with Professor Robert West warning they would give people a false sense of security.
The scale of the opposition presents a potential major problem for Mr Johnson if the plans require primary legislation to enact them.
And last night, a Whitehall source told the Mail ministers would try to win round furious Tory MPs by reassuring them that any new passport scheme would be temporary.
While no decision has been taken on how long any scheme should last, the source said it was likely to be no more than a year.
'It will be time-limited and I think the duration of the scheme will be measured in months,' the source said.
'The party will not wear any longer.'
The move came ahead of a major announcement by the PM on Monday where he will address not just vaccine passports, but the Government plans for holidays and the next phase of lockdown
Culture Secretary Oliver Dowden yesterday defended the idea of so-called 'Covid status certification', saying it could help people get back to 'doing the things they love', such as going to the theatre or attending live concerts and sports events.
Ministers are hoping to pilot the use of vaccine passports at major events within weeks, with the FA Cup final and the World Snooker Championship among those being considered for trials.
Mr Dowden stressed that vaccine status is only one element of the scheme, with people also able to show a negative Covid test or prove they have already had the virus to gain entry.
He told the BBC: 'This is not about a vaccine passport, this is about looking at ways of proving that you are Covid secure, whether you have had a test or had the vaccine. Clearly, no decisions have been made on that, because we have to weigh up different factors, the ethical considerations and so on, but it may be a way of ensuring we can get more people back doing the things they love.'
But Tory critics of the idea yesterday stepped up their opposition – and warned that a time limit would not be enough to tackle their concerns.
Former minister Steve Baker warned that any temporary scheme could be renewed – and pointed out that income tax had started life as a temporary measure.
Mr Baker, deputy chairman of the 70-strong Covid Recovery Group of MPs, said: 'MPs and the public shouldn't kid themselves. The state has always wanted ID cards, so this scheme would be about as temporary as income tax – in other words, permanent.'
Fellow Tory Andrew Bridgen said backbench opposition was based on principle rather than the duration of any scheme.
Mr Bridgen described the idea as a 'vision of hell', adding: 'Who would have thought the British public would ever have to show their papers to go to the pub? The whole idea is like something out of North Korea, and I hope that the strength of feeling, not just on the Conservative benches but across Parliament will stop the Government heading off in this direction.'
Some 41 Conservative MPs signed the pledge against vaccine passports organised by the pressure group Big Brother Watch – enough to wipe out the Government's 80-strong majority.
One MP said the fate of vaccine passports was now 'in Keir Starmer's hands'.
The Labour leader suggested this week the idea of vaccine passports went against the 'British instinct', but party sources said voting decisions would depend on the detail of the Government's plans.
Shami Chakrabarti, the former shadow attorney general, launched an impassioned attack on the idea of creating a 'Checkpoint Britain'.
Baroness Chakrabarti, a former director of the civil rights group Liberty, told BBC Radio Four's Today programme: 'It's dangerous, it's discriminatory, it's counter-productive... 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.'
Professor West, a member of a sub-group of the Government's expert scientific committee Sage, said the 'balance of evidence' was against the idea.
He told Times Radio it would be 'discriminatory' to require vaccine certificates in everyday situations such as bars and restaurants, as some people are unable to have the vaccine.
He added that the scheme could give a 'false sense of security' to people who might fail to understand that the vaccine cannot give 100 per cent protection against disease.
It also came as revellers tonight kicked off the four-day Easter weekend as police were forced to break up crowds in Cardiff, Exmouth and Plymouth.
Police sent revellers packing tonight after fights broke out when around 40 people gathered for a party on a beach in Devon despite the ongoing rule of six.
Footage taken by a walker showed more than 100 people along Plymouth Hoe as crowds ignored social distancing measures and in Cardiff photographs showed crowds cramming close together at Cardiff Bay as the sun started to set this afternoon.
It comes after police stepped up patrols and begged parents to control their children over the four-day break, in the wake of carnage seen across the country this week.