Travellers returning to the UK from Spain will have to quarantine for 14 days from Sunday, the BBC understands.
It is believed the measures will come into force in the early hours of Sunday.
The UK government is expected to announce the change imminently, due to a significant spike in coronavirus cases in Spain.
Spain has warned a second wave could be imminent as cities including Madrid and Barcelona have seen cases surge.
The government of Catalonia has also said all nightclubs and late-night bars in the region are to close for the next two weeks due to a spike in infections.
The Spanish health ministry reported more than 900 new cases of the virus on Friday.
The UK government updated its list of countries exempt from the two-week quarantine rule on Friday, but Spain still remained on the list.
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