Air bridges have been proposed as a way of ensuring more travellers can be excluded from the incoming 14-day quarantine.

Here the PA news agency looks at eight key questions around the issue:

– What is an air bridge?

Air bridges would involve passengers travelling between the UK and specific destinations not needing to self-isolate for 14 days after arriving in the UK.

– What routes could be considered?

They would be implemented on routes between countries deemed at low-risk of spreading coronavirus.

Visit Britain chief executive Patricia Yates has said the tourism industry would benefit from air bridges with countries such as the US, France, Germany and Italy.

– How quickly could they be introduced?

Quarantine rules will be reviewed every three weeks, meaning air bridges could be installed by the end of June.

– Why has this been proposed?

There is concern that people will not take overseas holidays, and foreign tourists will not visit the UK, if they have to go into quarantine for 14 days.

– Who is in favour of air bridges?

Support for air bridges has been given by hundreds of UK travel and tourism businesses, a number of senior Conservative MPs and Portugal’s foreign minister.

– What about Boris Johnson?

Reports suggest the Prime Minister is in favour of air bridges.

His official spokesman said on Tuesday that the Government is still looking at the suggestion.

On a Portuguese beach you are less at risk than a UK beach

– What has the Transport Secretary said?

Grant Shapps said the Government is working with the transport industry “to see how we can introduce agreements with other countries when safe to do so, so we can go abroad and tourists can come here”.

– What do scientists think?

Professor Keith Neal of the University of Nottingham said people from the UK who visit countries with less disease and maintain social distancing will be at a lower risk of being infected.

“On a Portuguese beach you are less at risk than a UK beach,” he explained.