His comments came as he defended his decision to quarantine travellers arriving back in the UK from Spain, where cases have spiked.
Boris also urged Brits to be “vigilant” as he alluded to Government worries about a second wave hitting British shores.
Speaking as he launched his big push to promote cycling, Boris opened up about the number of rising cases on the continent.
He said: “Let’s be absolutely clear about what’s happening in Europe, amongst some of our European friends. I’m afraid you are starting to see in some places the signs of a second wave of the pandemic.”
Boris defends quarantine decision
Boris then went on to defend his quarantine decision.
It has been pretty unpopular with Brits who are currently on holiday in Spain.
“What we have to do is take swift and decisive action where we think that the risks are starting to bubble up again,” he said.
Then he issued his plea to the country.
He said: “We just have to be vigilant and we have to be very mindful.”
I’m afraid you are starting to see in some places the signs of a second wave of the pandemic.
The Foreign and Commonwealth Office has now advised against all but essential travel to Spain.
Number 10 also warned that no overseas travel is without its risks during the pandemic.
“No travel is risk-free during this pandemic. Anyone travelling abroad should be aware that our travel advice and exemption list is under constant review as we monitor the international situation,” the rep said.
Boris added that it was up to individuals if they did choose to travel abroad.
“We will continue to take action”
“These are decisions for families, for individuals, about where they want to go,” he said.
He also reiterated the need for Brits to comply with the quarantine measures.
“It’s vital that when people are coming back from abroad, if they are coming back from a place where I’m afraid there is another outbreak, they must go into quarantine,” he said.
Boris added: “That’s why we have taken the action that we have and we will continue, throughout the summer, to take such action where it is necessary.”
He concluded: “I’m afraid if we do see signs of a second wave in other countries it is really our job, our duty, to act swiftly and decisively to stop travellers coming back from those places seeding the disease here in the UK.”
Head to our Facebook page @EntertainmentDailyFix and tell us if you’re worried about a second wave.