Prime Minister Boris Johnson has confirmed that all travellers arriving in the UK will be quarantined for 14 days.
In his address to the nation this evening Mr Johnson said that in order to prevent re-infection from abroad he was "serving notice".
"I am serving notice that it will soon be the time – with transmission significantly lower – to impose quarantine on people coming into this country by air," he said.
It was not outlined tonight how long this may have to go on for as the Prime Minister did not address a specific timescale.
But according to government sources, quarantine will be for 14 days.
Some people have criticised the government for not imposing this measure sooner with other countries such as Australia, New Zealand and Singapore already having introduced similar measures.
However, Mr Johnson says it is only now that it will be effective.
He explained: "It is because of your efforts to get the R down and the number of infections down here, that this measure will now be effective."
The PM is expected to give further details on this measure in the coming days.
The quarantine measure is one of a set of new rules, intended to help avoid a deadly second wave of coronavirus infections as lockdown restrictions are gradually eased.
The Times had previously reported that anyone who is caught failing to adhere to the new measure could be fined up to ￡1,000 or be deported from the country.
It said that passengers will be asked to give Border Force officials an address where they will spend their quarantine via a digital form.
Authorities are set to carry out spot-checks to ensure the measure is followed.
The rules will not apply to travellers from Ireland.
Shadow foreign secretary Lisa Nandy was asked about the 14-day quarantine for people flying into the UK last week.
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The Labour MP told BBC Breakfast: "It's something that we've been asking ministers to clarify for weeks now.
"I raised it with the minister for the fifth time on Thursday because it's caused real confusion.
"At the moment we've got a lot of Britons who are still stranded abroad.
"People have been brought back in relatively large numbers and many of them are telling us that they have no information or advice given out about what they should be doing when they get home.
"They travel back from the airport on public transport, they go back to their families and they're worried that they're putting their families and other members of the public at risk, and some of them are coming from parts of the country where we are seeing an increase in infection rates, and so they're really worried about it, the wider public are really worried about it, and for weeks we've had mixed messages being briefed out of government."
The aviation industry has warned that the proposal could have severe repercussions for the travel and tourism sectors.
In a statement, Airlines UK, which represents British Airways, EasyJet and other UK-based airlines, said mandatory quarantine "would effectively kill international travel to and from UK".
It added: "Nobody is going to go on holiday if they're not able to resume normal life for 14 days, and business travel would be severely restricted.
"It will also make it all but impossible for aviation to resume any time soon, thereby setting back the UK's economic recovery still further."