To enter nightclubs and some other venues, proof of two coronavirus jabs will be compulsory for most People queuing at nightThe queue for Egg nightclub in London as rules in England were initially unlocked at midnight on 19 July.Photograph: Jonathan Brady/PA

What changes have ministers announced?

The main one is the full introduction of what might be called domestic vaccine passports: from the end of September, people in England will have to prove they have had both Covid doses to enter nightclubs, as well as for what are described as “other venues where large crowds gather”.

How is this different to what is in place now?

It is a change of policy on two fronts. Firstly, under the fourth and supposedly final stage of unlocking, which began on Monday, all businesses were able to reopen without any distancing or Covid entry requirements, including nightclubs. Such venues have been “encouraged” to use some sort of Covid certification but this is not mandatory. The other change is that previous incarnations of domestic Covid certification plans have not been based solely on jabs but also allowed people to prove their status with a recent negative Covid test or one showing Covid antibodies. Under the new plans, it will be double vaccination only.

Will there be exemptions?

Yes. People who have “genuine medical reasons of why they can’t get vaccinated” will not be subject to the scheme. Details of who will be included within this have not yet been released.

Why is this being done?

For several reasons. One is to do with concerns about the potential scale of Covid infections among crowds of younger, often unvaccinated people pressed closed together in enclosed, noisy spaces. The wait until the end of September is designed to allow all over-18s to be offered both jabs, and an extra two weeks for these to become effective. Such a policy will also provide a strong incentive for younger people to be vaccinated.

Is this new?

Yes, for domestic use. Mandatory double vaccinations are necessary for a lot of international travel, both in terms of other countries’ entry requirements and to avoid quarantine if returning from amber-list destinations. But this will be the first time any sort of domestic Covid certificate will be compulsory to enter certain businesses, plus it is the first vaccine-only incarnation beyond international travel.

Earlier this month the government’s official review into Covid certification said: “The government has concluded that it will not mandate the use of Covid-status certification as a condition of entry for visitors to any setting at the present time.” Even other countries that have used Covid certification, such as Israel’s green pass – which had far more wide-ranging use – was not restricted to vaccination only.

Could pubs and other venues be included?

It depends. At the Downing Street press conference where he unveiled the plan, Boris Johnson was asked if the domestic passport scheme could be extended to people going to pubs. Johnson said he did not want to “get to the situation where people are asked to provide papers to go anywhere”, but did not completely rule it out. They are deemed appropriate for settings with the three Cs – “closed spaces, crowded places and close-contact settings” – the press conference was told.

What will the reaction be?

Two main groups are likely to be concerned, with some crossover. One will be rights organisations. In April, when the idea was first being considered, the Equality and Human Rights Commission said internal Covid passports risked creating a “two-tier society”, although this was at a period when a much lower percentage of people had received jabs. The other group will be Conservative MPs from the more lockdown-sceptic wing of the party, notably the Covid Recovery Group. When news of the scheme emerged, Steve Baker, deputy chair of the group, re-sent a tweet in which he warned that ministers “must not restrict basic freedoms only to restore them to some”. David Davis said it was “astonishing” that the rules excluded test status. The Liberal Democrats, meanwhile, called the plan “unworkable, expensive and divisive”.

What about other new Covid rules?

There will be another immediate change to allow workers in a small number of critical professions, such as health and care staff, to avoid having to self-isolate if they have been in close contact with someone who tested positive for Covid, as long as they record negative tests. This will include professions such as air traffic control, transport staff, border officials and people involved in supplying food, water, electricity and medicines.