The mandatory 10-day stay in government-provided accommodation, first announced last month, is designed to tighten borders against new variants of the coronavirus which could endanger Britain’s vaccination programme.
Opposition lawmakers have criticised Boris Johnson’s government for not implementing the plan more quickly, saying the delay was putting lives at risk.
The prime minister said on Wednesday details would be announced on Thursday, only to be contradicted by his spokesman less than 24 hours later.
In the announcement, the government said it had been consulting the travel and hotel industries, and would now finalise plans, including contracting hotels near ports and airports.
Health Secretary Matt Hancock had discussed the policy with his counterpart in Australia, where quarantine was introduced in March 2020, the Department of Health and Social Care (DHSC) said. Officials would also seek advice from New Zealand.
A DHSC spokeswoman said Britain already had one of the toughest border regimes in the world for travellers, such as requiring proof of a negative COVID-19 test.
“We are now working at pace to secure the facilities we need to roll out managed quarantine for British nationals returning home from the most high risk countries,” she said.
“In the face of new variants, it is important that the government continues to take the necessary steps to protect people and save lives.”
The quarantine will apply to countries on a “red list” where COVID-19 variants are prevalent, including South Africa and countries in South America.
The government in Scotland said on Tuesday it planned to require everyone arriving directly into Scotland from overseas to quarantine, regardless of where they have come from. Reporting by Paul Sandle, additional reporting by Elizabeth Piper in London and Derek Francis in Bengaluru; Editing by Marguerita Choy