Boris Johnson would be “perfectly happy” to receive the Oxford/AstraZeneca coronavirus vaccine, Downing Street has said.

The prime minister’s full support for the jab came after several European countries paused its use due to concerns over possible adverse side effects such as rare blood clots.

As a 56-year-old, Johnson is eligible for the latest rollout of the vaccines in the UK but has yet to receive his own jab.

Asked directly about the vaccine, his spokesperson said: “He would be perfectly happy to take the Oxford/AstraZeneca vaccine.

“There’s no evidence of any casual link between blood clots and the AstraZeneca vaccine.”

The remarks came as Emer Cooke, the European Medicines Agency (EMA) executive director, said there was no indication AstraZeneca vaccine was the cause of reported blood clots.

“I want to also stress at present there is no indication that vaccination has caused these conditions,” she said.

“They have not come up in the clinical trials and they are not listed as known side events with this vaccine.”

Earlier, foreign secretary Dominic Raab said: “I can tell you crystal clear that the UK regulator, the European EU regulator and the WHO all say that the AstraZeneca vaccine is safe and people should continue to take it.”

And leading scientists warned that pausing the rollout of the vaccine in Europe could be a “disaster” for uptake.

Peter Openshaw, professor of experimental medicine at Imperial College London, insisted people who are booked in to receive the AstraZeneca jab should not be worried.

Speaking on BBC Radio 4’s Today programme, he said: “I think it is very clear that the benefits of being vaccinated at the moment so far outweigh the possible concern over this rather rare type of blood clot.

“It really is a completely one-sided argument statistically that we need to be vaccinating.

“I think it is a disaster for the vaccination uptake in Europe, which is already on slightly unsteady ground in some countries.”