Rishi Sunak Faces One of His Toughest Weeks as U.K. Prime Minister

Prime Minister Rishi Sunak of Britain embarked on one of the most politically fraught weeks of his tenure on Monday, facing a mutiny against his flagship immigration policy while testifying before an official inquiry into the coronavirus pandemic about whether he had contributed to driving up infections.

On a day of split-screen drama in the capital, Mr. Sunak expressed sorrow for Britain’s heavy death toll from Covid-19, saying, “It’s important that we learn the lessons so we can be better prepared in the future.”

But he briskly rejected claims that one of his most conspicuous projects as chancellor of the Exchequer — subsidizing restaurant meals to shore up the economy — had accelerated a second wave of the virus in the fall of 2020. Other officials have testified that scientists were not consulted about the program, and viewed it as risky.

While Mr. Sunak was defending his role in the Covid response, right-wing Conservative Party lawmakers met a few miles across London to share doubts about his revised policy of putting asylum seekers on one-way flights to Rwanda. The legislation has fractured the party, alienating both Tory centrists, who worry that it goes too far, and right-wingers, who contend it does not go far enough.

Legal experts for the European Research group, a caucus of right wing lawmakers, concluded that the bill provides only “a partial and incomplete solution” to the legal problems that have thwarted previous versions of the policy, and said that “very significant amendments” were needed. Some called on Mr. Sunak to pull it.

With a parliamentary vote scheduled for Tuesday, Mr. Sunak faces the possibility of a rebellion that would torpedo the Rwanda policy. If lawmakers pass the plan, it could still face a string of amendments, as well as a hostile reception in the House of Lords, the unelected upper chamber of Parliament.

A defeat would deal a crippling blow to Mr. Sunak’s authority, given that he has pledged to stop the flow of boats carrying asylum seekers across the English Channel. It could even trigger yet another leadership crisis for a party that has churned through five prime ministers in the last seven years.

For Mr. Sunak, it adds up to a devilishly difficult few days.

At the Covid hearing, the prime minister did his best to lower the temperature. He was careful not to criticize his predecessor, Boris Johnson, whom he had served under during the crisis, and who faced intensive questioning last week over his own much-faulted performance during the pandemic.

But Mr. Sunak showed a flash of anger when the inquiry’s chief counsel, Hugo Keith, referred to claims that his restaurant stimulus program, “Eat Out to Help Out,” had driven up infection rates by encouraging groups of diners to eat indoors in close physical proximity. The inquiry was told earlier that England’s chief medical officer, Chris Whitty, referred to the program in his diary as “Eat out to help out the virus.”

Visibly frustrated, Mr. Sunak said nobody raised those concerns in the weeks between the announcement of the program and its implementation. And he denied there was evidence that the program had spread the virus.

“There was plenty of opportunity for people to have raised it either with me or with the prime minister,” Mr. Sunak said. “I’ve outlined my reasons for why we implemented the policy and why we thought it was the right thing to do. I believe it was the right thing to do to safeguard those jobs.”

Mr. Sunak complained there had been an “undue focus on this one item,” prompting Mr. Keith to interrupt sharply, “Excuse me?” He reminded the prime minister that it was up to the inquiry’s chairwoman, Heather Hallett, to determine “whether or not they are of importance to this inquiry.”

As soon as Mr. Sunak stepped away from the witness table, he faced a difficult lobbying effort to keep his flagship Rwanda immigration policy alive. Mark Francois, who chairs the European Research Group, said the prime minister would be “best advised to pull the bill and to come up with a revised version that works better than this one, which has so many holes in it.”

Assuming the government ignores that advice and goes ahead with the vote, the scale of Conservative opposition could have wide-ranging consequences for Mr. Sunak. To win, he needs to keep the rebellion among Conservatives to below 28 lawmakers voting against the bill, or 56 abstaining.

Some right-wing critics may prefer to allow the legislation to pass and to try to amend it later. But moderate Tories believe that the bill already goes too far in overriding human rights laws — so with rebellious lawmakers on opposite wings of the party, there is a possibility they could combine to defeat the bill by accident.

If enough on the right of the party abstain, and a number on the left vote against or also refuse to support it, Mr. Sunak could lose, said Philip Cowley, professor of politics at Queen Mary, University of London. “But it’s likely that they will get it through with a reduced majority, with a lot of people deliberately keeping their powder dry for the later stages.”

That would merely postpone the confrontation, given that the government now argues that it has gone as far as it can without risking a breach of international law that would prompt Rwanda’s government to pull out of the deal.

For Mr. Sunak, Professor Cowley said, the critical thing is to keep the Rwanda policy alive so that during a general election that is expected next year, he can blame the opposition parties for blocking the plan.

Last year the Tories replaced their leader twice, eventually installing Mr. Sunak who has failed to improve the party’s dismal polling ahead of an election that must take place by January 2025.

With some Tory lawmakers assuming that an electoral defeat is unavoidable, party discipline has unraveled and some now even regret their decision to oust Mr. Johnson from Downing Street last year, according to British media reports that are full of speculation about an unlikely return for the former prime minister.

Conservative right-wingers are also concerned about being outflanked by Reform U.K., a fringe right-wing party and the successor to the Brexit Party which was led by Nigel Farage, a leading campaigner for Britain’s exit from the European Union.

Mr. Farage has spent recent weeks taking part in a reality TV show at an Australian jungle camp, during which his trials included lying in a metal container as snakes slithered over him. Asked on Monday about a return to politics, a smiling Mr. Farage, who has failed several times to win election to the British Parliament, told ITV, “Never say never.”