The Vote That Could Derail Sunak’s Government, Explained

Prime Minister Rishi Sunak of Britain faces a crucial test of his authority on Tuesday, as he attempts to quell a rebellion from the hard right of his party.

At issue is a highly contentious immigration policy that aims to deter asylum seekers from crossing from France to Britain on small boats by putting hundreds of them on one-way flights to Rwanda.

Both Mr. Sunak and the potential right-wing rebels regard the project as key to the prospects of the governing Conservative Party.

The Conservatives have chosen to make tackling immigration a central theme in recent years, announcing hard-line measures aimed at deterring migrants from even trying to reach Britain. On Tuesday, it was announced that a man had died on a barge that the government had hired to house asylum seekers, the Bibby Stockholm, piling additional pressure on Mr. Sunak over his government’s treatment of migrants.

But so deep are the divisions with the party, which has held power for 13 years and is significantly behind in the polls, that Tuesday’s vote on the Rwanda policy has revived memories of the crisis after Britain voted to quit the European Union in 2016. That generated a succession of knife-edge votes in Parliament, plunged the country into political gridlock and ended with the prime minister, Theresa May, losing her job.

What is this crucial vote all about?

Under the government’s plan, some of those arriving on small boats would be deported to Rwanda to have asylum claims heard there. Even if they were then recognized as refugees, they would then be invited to stay in the small African country rather than receiving permission to live in Britain.

Tens of thousands of people have been making the dangerous journey across the English Channel each year, often on unseaworthy boats. And, while the numbers are small compared with the scale of legal immigration to Britain, the arrivals are a highly visible and embarrassing symbol of the failure of one of the central promises of Brexit campaigners: to control Britain’s borders.

The Rwanda policy was introduced under the government of Boris Johnson in 2022, and was immediately criticized by human rights groups and legal experts, who warned that it was likely to be unworkable given Britain’s commitments under international law. The government plowed ahead, and Mr. Sunak committed to the plan when he became prime minister last year.

Yet, despite the government spending or pledging a total of 290 million pounds — about $310 million — on the project so far, not a single asylum seeker has been flown to Rwanda. Britain’s Supreme Court ruled this year that Rwanda was unsafe for asylum seekers, and that some might be sent on to their countries of origin where they could be in danger. The new legislation aims to address the court’s objections.

Why is the bill so contentious?

The legislation proposes overriding some human rights law and, critics say, comes close to breaching international obligations. Courts would be told to set aside sections of Britain’s Human Rights Act, and the government could ignore emergency orders from the European Court of Human Rights to suspend a flight while a legal case was heard.

The bill also states that “Every decision maker must conclusively treat the Republic of Rwanda as a safe country,” contradicting the judges on a point of fact and forcing immigration officials, the home secretary and the courts to abide by this. The government says that it has assurances from the Rwandan government, enshrined in a new treaty, that all asylum seekers will be allowed to remain in the country even if their claims fail. But critics argue that declaring Rwanda is safe when the Supreme Court said the opposite is like declaring that black is white.

So the bill is pretty tough?

Indeed, it’s almost too tough for the One Nation Group, a caucus of Conservative lawmakers from the center and left of the party, which seems ready to support the legislation in its current form but not if it is hardened any further. According to Mr. Sunak, the Rwandan government has also threatened to pull out if Britain goes any further toward breaking with international law.

But the bill is not tough enough for the Conservative Party’s right wing. An immigration minister, Robert Jenrick, resigned from the government last week saying the bill did not go far enough. On Monday, legal experts for the European Research Group, a right-wing caucus which tormented Mrs. May during the Brexit drama, declared the bill “a partial and incomplete solution” to the legal problems that have so far grounded flights to Rwanda and said that “very significant amendments” were needed.

Right-wingers want the government to close off all routes for individuals to appeal against deportation and think Britain should to be prepared to leave the European Convention on Human Rights if necessary. Some want the government to withdraw the bill and start again.

What are the chances that Mr. Sunak wins the vote?

At this stage, pretty good, according to most political commentators. The government has worked hard to court potential rebels. But any victory could be temporary.

On Tuesday night, lawmakers will be asked only to approve the measure in principle. There will be opportunities to amend the legislation later on, and it’s also likely to face fierce opposition in the unelected upper chamber of the British Parliament, the House of Lords.

So critics could hold their noses and vote for the bill, while planning to change it later. Or Mr. Sunak’s internal opponents could abstain instead.

The main opposition Labour Party opposes the bill, as do smaller parties. So, to keep the policy alive, the prime minister can probably tolerate no more than 28 Conservatives voting against the bill, or 56 abstaining, though if some oppose it and others choose not to vote the math could get complicated.

If Mr. Sunak calculates that he would lose, he could always withdraw the legislation, but that would be such a humiliation that it would be only a last resort.

And what happens if he loses?

A defeat would represent the biggest and most damaging blow yet to Mr. Sunak’s already shaky leadership. The Conservatives trail the opposition Labour Party by around 20 points in opinion polls, with a general election expected next year.

So in a party that dispensed with two prime ministers last year, there is some talk on the right of choosing yet another — although the Conservatives’ chairman, Richard Holden, said last week that instigating another leadership election would be “insanity.”

Mr. Sunak’s problem is that he has put the Rwanda plan at the heart of his political agenda. Without the bill, his flagship policy would be in tatters — just as Mrs. May’s Brexit plan was when she was repeatedly defeated in Parliament. And, given the divisions within the Conservatives, even if the bill passes on Tuesday, the conflict over the policy may simply have been postponed.