The mutated coronavirus strain first identified in England is cropping up in more cases abroad.
So far, no other country has double figures of cases and all the new infections are traceable to the UK, but that is expected to change.
With flights from the UK already banned by many countries, other border closures are being considered.
UK Transport Secretary Grant Shapps said Britain was simply seeing first what was already at large in other countries.
"We've detected that first, but we know already that cases have been found in continental Europe and other countries, including countries which have placed travel bans, The Netherlands, for example, actually has much higher case rates per 100,000 than the UK at the moment," he said.
Experts face a waiting game to see how widespread the strain will become and how much more contagious it is.
By Monday afternoon, the Netherlands had reported one case of the new strain. The country is a short ferry trip from the UK across the North Sea.
Belgium has four cases. The country also has rail and ferry routes into the south of England.
Denmark has nine cases, all so far linked back to Britain. Sweden announced on Monday that it was closing the border with its neighbour.
“Denmark has also had an increased spread lately and elected to close down, for example, all shopping malls during Christmas and the holidays. There is an obvious risk that Danes will be tempted to cross over to Sweden to shop for Christmas presents," Home Affairs Minister Mikael Damberg said.
Italy has one case. The Ministry of Health confirmed a patient infected with the new strain was identified at the Celio military hospital in Rome. The patient had recently returned from Britain by plane and he and his relatives are in isolation, according to the same source.
Australia has reported at least two suspected cases, which are also believed to have originated in UK. The variant was detected in two passengers who landed in New South Wales after flying from the UK, said Kerry Chant, the state's chief health officer.
Elsewhere, initial reports of a case in South Africa appear to be unfounded. A mutation has been identified there but does not appear to share all of the characteristics of the UK strain.
There are also unconfirmed reports of a case in Gibraltar, a British Overseas Territory in the Mediterranean close to Spain.