One of the Democratic Party’s most senior figures has openly criticised the UK’s system for approving a Covid-19 vaccine, suggesting that the process for ensuring its safety is not as rigorous as that followed in America.
Nancy Pelosi, the Democratic speaker of the House of Representatives - one half of the US Congress - made the unexpected comment during a press conference on Friday.
She said that people must be “very careful” about the UK drive to approve a vaccine, suggesting that America's Food and Drug Administration (FDA) had a tougher criteria for screening any vaccine than its equivalent in Britain.
Oxford University and the drugs company AstraZeneca are working together on a possible vaccine for Covid-19 and are further along the timeline of trials than other similar vaccines being worked on by others.
The timing of the comments suggests there could be a reflection of political calculation, given Mr Trump appears eager to declare a coronavirus vaccine has been secured before the election and one of the leading candidates is being researched in the UK.
Ms Pelosi is also on record in the past of being a critic of Boris Johnson, recently warning that if the Prime Minister followed through with his proposal to rewrite parts of the Brexit. Withdrawal Agreement it could jeopardise a UK-US free trade deal.
Mr Pelosi said: "I think we have to be very careful about what happens in the UK.
"We have very stringent rules in terms of the Food and Drug Administration here about the number of clinical trials, the timing, the number of people and all the rest so that when a drug is approved by the FDA and the scientific advisory committee that it is safe and efficacious then it will have the trust of the American people to take it.
“Vaccines are about trust and we want people to take it.
“So we pray that it is soon, the sooner the better, not one day sooner than it is safe and efficacious but not one day later either.
"And my concern is that the UK’s system for that kind of judgment is not on a par with ours in the United States.
"So if Boris Johnson decides he’s going to approve a drug and this President embraces that, that’s the concern that I have about any similarity between the two.”
A spokesman at the UK Department of Health and Social Care responded: "The UK has some of the most robust standards for approving new treatments and vaccines in the world.
“Any vaccine must go through clinical trials in line with international standards, with independent oversight provided by the Medicines and Healthcare products Regulatory Agency, which has vast experience in ensuring the delivery of safe and effective vaccines."