Boris Johnson's plan to ask nightclubs and other venues with large crowds to adopt Covid passports from Monday could put unvaccinated patients off receiving a jab, according to a statistician.
An ORB survey of more than 2,000 people found that, of respondents who had yet to receive a vaccine but were open to the idea, 44 per cent may be less likely to accept a jab if Covid certification became a requirement at clubs, theatres and sporting events.
Of those who said they were unsure whether to accept a vaccine, only 17 per cent said the policy would make them more likely to have a jab.
The findings raise the prospect that the use of vaccine passports as part of the re-opening of venues such as nightclubs could damage the Government's attempts to convince waverers to have a jab.
Alex de Figueiredo, the statistics lead at the London School of Hygiene and Tropical Medicine's Vaccine Confidence Project, said the findings showed the Government needed to be "exceptionally careful" with the idea of vaccine passports.
"We cannot confuse majority public support with a public health benefit," he said, adding that passports were generally only popular with those who had already expressed a firm intention to get a vaccine.
Dr Figueiredo's analysis of the polling showed that the introduction of vaccine passports could lead to a 27 per cent "net decrease in agreement to accept a vaccine".
Some 427 people of those polled had yet to receive a jab. Of those, 55 per cent said they "definitely will" accept one or were "unsure but leaning to yes” while 45 per cent said they were "unsure but leaning towards no" or "definitely will not” have a jab.
Sixty-six per cent of the 2,046 respondents said they would feel more comfortable attending nightclubs, theatres and sporting events that insisted on Covid certification. The same proportion agreed with Boris Johnson's suggestion that certification should become a legal requirement if venues failed to introduce such systems for themselves.
But of respondents who were unsure about whether they would accept a vaccine, only 17 per cent said the passports policy would make them more likely to have a jab.
Some 44 per cent of those who had yet to receive a jab but were open to one disagreed with the statement that they would be more likely to accept a vaccine if Covid passports were introduced at leisure venues.
Overall, only 28 per cent of people said a vaccine passport requirement would make them less likely to visit theatres, clubs and other large venues, while 58 per cent disagreed. But among those who had not yet had a vaccine, the proportion who said they would be less likely to go into such venues rose to 44 per cent.
The findings chime with an earlier survey of more than 16,000 people which found that the introduction of vaccine passports could reduce uptake of jabs in cities, leading to "concentrated areas of low vaccinate uptake" and heightening the overall "epidemic risk".
The earlier study, also by the The Vaccine Confidence Project, concluded that in London and Northern Ireland and among black communities, there was still "much work to do" to convince people to have vaccines.
The survey also suggested a sharp rise in those believing that Covid is not under control, with 70 per cent now disagreeing.
Last week, Mr Johnson said nightclubs and other venues with large crowds would be urged to adopt Covid certification "as a matter of social responsibility".
He said relevant businesses should "make use" of the NHS Covid app, which shows proof of double vaccination, a recent negative test or natural immunity, as "a means of entry".
It marked a climbdown by the government after Nadhim Zahawi, the vaccines minister, insisted in February that "we are not planning to have a [Covid] passport in the UK".