(Bloomberg) -- Boris Johnson’s most powerful political aide pressed the U.K.’s independent scientific advisers to recommend lockdown measures in an effort to stop the spread of coronavirus, according to people familiar with the matter.

The government has confirmed that Dominic Cummings was an observer at some meetings of its Scientific Advisory Group for Emergencies (SAGE), the secretive body which gives specialized advice to ministers on responding to the pandemic.

According to two people involved, Cummings played far more than a bystander’s role at a crucial SAGE meeting on March 18, as the panel discussed social distancing options to tackle the Covid-19 outbreak.

Speaking on condition of anonymity because the meetings are private, the people said Cummings asked why a lockdown was not being imposed sooner, swayed the discussion toward faster action, and made clear he thought pubs and restaurants should be closed within two days. They then were.

The prime minister’s office denied that political advisers influenced the experts on the SAGE committee and said it was appropriate for aides to sit in on meetings and to ask questions. The two people who took part in the meeting said Cummings’s actions went further than simply asking for information.

The suggestion that Cummings influenced the group’s lockdown decisions is likely to cast doubt on the government’s assurances that it has simply followed scientific advice throughout the crisis. As the death toll continues to rise, that could put Johnson in a more difficult position as he seeks to deflect criticism of the government’s response.

The Week Coronavirus Got Away From Boris Johnson’s Government

Powerful Aide

Cummings has been a hugely controversial figure at the heart of the government ever since he was appointed to be Johnson’s chief adviser last July.

The pair worked closely on the pro-Brexit campaign, which Cummings masterminded, and then set about continuing their political revolution in government -- ripping up establishment rules and purging the Conservative Party of Johnson’s critics after he became prime minister last year.

His role in shaping the U.K.’s much-criticized Covid-19 strategy has been less clear. Johnson’s office vigorously denied claims made in a British newspaper that Cummings originally wanted a policy of so-called herd immunity, even if it meant some older people would die. On March 30, it emerged that Cummings -- like his boss Johnson -- was in isolation with coronavirus symptoms.

Top U.K. Aide Cummings Self-Isolates With Coronavirus Symptoms

The Guardian revealed on Friday that Cummings had attended meetings of the scientific advisory panel, known as SAGE, and the Observer newspaper on Sunday said he’d been an active participant in discussions.

But the disclosure that he was so vocal in the debate over lockdown raises questions about his influence on the group’s ultimate recommendations.

Herd Instinct

It is “quite possible” that interventions from the prime minister’s most senior aide swayed discussions, said former U.K. chief scientific adviser David King. “There is a herd instinct in all of us – we call it groupthink,” King, who served during Tony Blair’s premiership from 2000 to 2007, said in an interview. “It is possible that a group is influenced by a particularly influential person.”

At the March 18 meeting, Cummings asked probing questions such as why the government should wait until the following week to impose a lockdown rather than doing so earlier, according to one of the people. He also said the public should not be allowed to leave work on March 20 and go to the pub afterward. The government ultimately told pubs and clubs to close on that day, before imposing a fuller lockdown that shuttered most shops on March 23.

One attendee at the meeting described feeling uncomfortable that the panel with Cummings’s input was taking more of a decision-making approach than simply drawing up options and giving advice to ministers. The attendee added, however, that it was also a relief that Cummings had pushed for a lockdown because there were concerns that politicians had not fully understood how serious the coronavirus emergency had become.

According to one person, Cummings directly asked the group at one point: “What is the Prime Minister going to say?” That was a sign of how far the panel had moved from drawing up advice to taking a policy decision, something that should not happen in a meeting of scientific advisers, the person said.

No Observer

With the government coming under criticism in the U.K. for not locking down earlier, the accounts suggest Johnson’s most senior adviser understood the severity of the crisis and was pressing for action to be taken more quickly. Some on the panel clearly agreed. The advisers were heading toward recommending a lockdown soon anyway, one of the people said.

But the intervention from Cummings shifted the dynamic in favor of tightening the restrictions more quickly, one person said, adding: “He clearly wasn’t an observer.”

Johnson’s office said Cummings was not a member of the SAGE committee. “SAGE provide independent scientific advice to government. No political advisers influence this advice,” a spokesperson for the prime minister’s office said an emailed statement. “The scientists who contribute to SAGE are among the most eminent in their fields. It is completely wrong to imply their advice is in any way not impartial.”

Government officials attend or dial in to SAGE meetings “to listen to its discussions and occasionally ask questions which is essential at a time the government is dealing with a global pandemic,” the Downing Street spokesperson said.

The disclosure of Cummings’s role in SAGE meeting will add to calls for the body to be more transparent. The committee’s membership has not been officially revealed.

King, the former government chief scientist, said he had convened several emergency committees during his tenure to deal with crises including Avian Flu, SARS, Scrapie in sheep and foot-and-mouth disease. No political special advisers -- known in Westminster as “spads” -- ever sat in on them, he said.

“What I was very keen to establish was the science advice has to be apolitical,” said King. “I also don’t like the idea that a spad could report independently of me back to a minister or the prime minister what their understanding – as a non-scientist – of a scientific discussion was. That is a dangerous practice.”

©2020 Bloomberg L.P.