His comments came after a cross-party group of politicians including former Labour leader Jeremy Corbyn and Lib Dem leader Sir Ed Davey warned against the introduction of the certificates on the grounds that they would be “divisive and discriminatory”.

Sir Keir suggested that even the “British instinct” could be against them.

However, the Prime Minister appeared to back the idea during a trip to Middlesborough on Thursday.

When asked if vaccine passports were un-British, Mr Johnson said that they would definitely have a role to play when international travel resumes.

“On the issue of vaccine certification, there’s definitely going to be a world in which international travel will use vaccine passports", he said.

“You can see already that other countries, the aviation industry, are interested in those and there’s a logic to that."

The Prime Minister then appeared to go a step further in the same answer, referencing the need to provide "maximum confidence" to business and customers in the UK.

“I think when it comes to trying to make sure that we give maximum confidence to business and to customers here in the UK, there are three things – there’s your immunity, whether you have had it before, so you have got natural antibodies, whether you have been vaccinated, and then of course whether you have had a test.

“Those three things working together will be useful for us as we go forward.”

The Prime Minister defended the idea during a trip to Middlesborough

Last week, Mr Johnson said pubs and other venues could use vaccine passports, before backtracking slightly to clarify that this may only be introduced once all UK adults have been offered a vaccination.

Pub and hospitality bosses have raised concerns that a review into Covid status certification, led by Michael Gove, looks likely to recommend that venues will be required to demand "immunity proof" from customers, with the threat of fines for non-compliance.

They also criticised a requirement for customers to sign in individually on entry and a lack of clarity over whether payments inside will be allowed once outdoor hospitality resumes, expected on April 12.

Trade bodies UKHospitality, the British Beer and Pub Association and the British Institute of Innkeeping, said: "The Government has promised the country that we will be reopening but we are now being told that this will be with our hands tied behind our backs."

The PM is expected to reveal more details of the UK’s plans to resume travel overseas, as the country gradually lifts lockdown restrictions.

Spain and Greece have already signaled they would welcome British tourists this summer, provided they can prove they have received a coronavirus jab or a negative PCR test.

Currently, anyone trying to leave the UK without an essential reason is liable to be fined £5,000.

The government is reportedly considering create a list of ‘essential’ public buildings which could be banned from excluding members of the public who have not had a jab.

The cross party pledge, signed by 70 MPs states: “We oppose the divisive and discriminatory use of Covid status certification to deny individuals access to general services, businesses or jobs.”

Meanwhile, Welsh First Minister Mark Drakeford said there were “many practical and ethical issues” around the introduction of vaccine passports, which he said had been discussed with Cabinet Office minister, Michael Gove, but that there were also “positive prizes to be won”.

Joining Mr Drakeford at the press conference, Dr Frank Atherton, Wales’ chief medical officer, said the certificates proving vaccination could be necessary in order to travel internationally to countries which may require them to enter.

Earlier on Thursday, Mr Drakeford said he hoped Mr Johnson will rule out the resumption of foreign travel from May 17 date - the earliest possible date foreign trips will be permitted under the government’s road map out of lockdown.

He told Good Morning Britain: “I’ve long argued that it is over-optimistic, that it doesn’t reflect the risk of reimporting coronavirus from other parts of the world where there are new variants in circulation.”