The UK has identified 77 cases of the coronavirus variant first detected in South Africa, the health secretary has said.
Cases are linked to travellers arriving in the UK, rather than community transmission, Matt Hancock added.
He told the BBC’s Andrew Marr cases were under “very close” observation and enhanced contact tracing was under way.
Ministers are due to meet on Monday to consider imposing tougher restrictions on people arriving from abroad.
Scientists have said there is a chance the South African variant may harm the effectiveness of current vaccines.
Meanwhile, Mr Hancock said 75% of over-80s and three quarters of care homes in the UK have received a first Covid jab.
Both the Pfizer-BioNTech and Oxford-AstraZeneca vaccines require two doses, and figures so far reflect those given the first dose.