Senior cabinet ministers are discussing whether to allow fully vaccinated travellers from the EU and US to avoid quarantine when they arrive in England.
A review of the border rules is due by 31 July - the second date in the Department for Transport's plan for a safe return to international travel.
The government's Covid Operations committee was due to meet on Wednesday morning.
Foreign Secretary Dominic Raab said a decision would be taken shortly.
Currently, people who have been fully vaccinated in the UK do not have to quarantine when travelling from the US and EU, apart from France, because those places are on the amber list (and some EU countries are on the green list). But that exemption does not apply to people who have been vaccinated outside the UK.
Downing Street and the Department for Transport declined to comment on newspaper reports the government would go ahead with the plan to also exempt people vaccinated in the US and EU.
The travel industry has been pushing for this change in the rules so that people living abroad can more easily come to the UK for holidays or to visit loved ones.
"At the moment we're in this slightly ridiculous situation where if I'm on a plane from Spain, because I'm lucky enough to have had two jabs, once we get to the UK I just wander off, no problem," said travel expert Simon Calder.
"But the person sitting next to me, who happens to have had their vaccinations in Spain, not in the UK, has to go and sit in a room for 10 days. Doesn't make sense."
