LONDON (AP) — British Prime Minister Rishi Sunak faces one of the toughest weeks of his 13 months in office as he’s grilled by lawyers about his decisions during the COVID-19 pandemic while fending off a rebellion from lawmakers over his signature immigration policy.

Sunak will be questioned under oath on Monday at a public inquiry into Britain’s handling of the pandemic, which left more than 230,000 people in the country dead. Sunak was Treasury chief to Prime Minister Boris Johnson when the coronavirus hit, and backed a discount initiative that encouraged people to go back to restaurants in August 2020 after months of lockdown.

The government’s scientific advisers have told the inquiry they were not informed in advance about the “Eat Out to Help Out” scheme, which scientists have linked to a rise in infections. One senior government science adviser referred to Sunak in a message to colleagues at the time as “Dr. Death.”

Johnson told the inquiry last week that the restaurant plan “was not at the time presented to me as something that would add to the budget of risk.”

While Sunak squirms during a scheduled six hours of testimony, lawmakers from his Conservative Party will be debating whether to support legislation intended to salvage his plan to send some asylum-seekers who arrive in Britain on a one-way trip to Rwanda.

The policy is key to Sunak’s pledge to stop unauthorized asylum-seekers from trying to reach England from France in small boats. More than 29,000 people have done so this year, down from 46,000 in all of 2022.

The plan has already cost the government 240 million pounds ($300 million) in payments to Rwanda, which agreed in 2022 to process and settle hundreds of asylum-seekers a year from the U.K. But no one has yet been sent to the country, and last month the U.K. Supreme Court ruled the plan illegal, saying Rwanda is not a safe destination for refugees.

In response, Britain and Rwanda have signed a treaty pledging to strengthen protections for migrants. Sunak’s government argues that the treaty allows it to pass a law declaring Rwanda a safe destination, regardless of the Supreme Court ruling.

That bill has its first vote in the House of Commons on Tuesday. Sunak faces dissent on two fronts — from centrist Conservative lawmakers concerned that the bill is defying U.K. courts, and from legislators on the party’s authoritarian wing who think the legislation is too mild because it leaves migrants some legal routes to challenge deportation.

The law, if approved by Parliament, would allow the government to “disapply” sections of U.K. human rights law when it comes to Rwanda-related asylum claims and make it harder to challenge the deportations in court. But it does not take Britain out of the European Convention on Human Rights, as some hard-liners demand.

If the bill passes its first vote on Tuesday, weeks of wrangling and more votes in Parliament lie ahead. Defeat would leave the Rwanda plan in tatters, and would threaten Sunak’s leadership.

Sunak believes delivering on his promise to “stop the boats” will allow the Conservatives to regain ground against the opposition Labour Party, which has a big lead in opinion polls ahead of an election that must be held in the next year.

But some Tory lawmakers think he is bound to fail, and are contemplating a change of leader. Under party rules, Sunak will face a no-confidence vote if 53 lawmakers — 15% of the Conservative total — call for one.

Others argue that it would be disastrous to remove yet another prime minister without a national election. Sunak is the third Conservative prime minister since the last election in 2019, after the party ejected both Johnson and his successor, Liz Truss.

Lawmaker Damian Green, a leading Conservative moderate, said anyone who wanted to change the party leader again is “either mad, or malicious, or both.”