Data comes as No 10 vows to press on with plan to make vaccination a condition of entry for nightclubs
Imposing vaccine passports is likely to make hesitant people even more reluctant to get Covid jabs, research involving more than 16,000 people has found as Downing Street vowed to press ahead with the plan within a month.
Boris Johnson announced in July that the government would make it compulsory for nightclubs and other crowded indoor venues to ensure customers have been fully vaccinated before allowing them entry.