With Northern Ireland and Migrants, Johnson Swings Cudgel of Survival Politics

LONDON — When Prime Minister Boris Johnson survived a potentially lethal challenge to his leadership last week, he said he wanted to pull politics in Britain back to “the issues I think the people in this country want to talk about.”

His first two issues, changing trade rules for Northern Ireland and flying migrants to Rwanda, certainly got people talking. But they also thrust Britain into a nasty web of legal disputes that risks making the country look like an international scofflaw. And they did so with policies that critics describe as flimsy, cynical and ineffectual.

A European court order forced Britain to ground a flight that was to transport seekers of British asylum to Rwanda on Tuesday night, setting off an angry chorus of complaints about foreign judges interfering in Britain’s efforts to police its borders. Mr. Johnson warned that Britain might leave the European Convention on Human Rights, an institution that Winston Churchill helped create after World War II. The last country to leave the convention was Russia, after its invasion of Ukraine.

Britain’s legislation to overhaul trade rules in Northern Ireland is widely viewed as a breach of its Brexit agreement with the European Union. On Wednesday, the bloc announced legal steps to retaliate. But a new clash with Brussels pleases the Brexiteers in Mr. Johnson’s Conservative Party and grabs headlines in pro-Tory newspapers that might otherwise dwell on economic woes or a scandal-scarred prime minister.

The ultimate success of both efforts is questionable: the trade legislation, because it will not take effect for at least a year, and Britain is wary of precipitating a trade war with Brussels in the meantime; the immigration policy, because it faces myriad case-by-case challenges and a broader judicial review next month.

Yet success, critics say, is beside the point. By whipping up a debate over British sovereignty, whether on asylum seekers or trade, Mr. Johnson is appealing to the pro-Brexit base in his party, as well as a pro-Brexit contingent in Parliament, whose support he needs to fend off another leadership challenge.

“This is not, and never has been, a serious policy, and she knew that when she chartered the plane,” the Labour Party’s representative on Home affairs, Yvette Cooper, said of the Home secretary, Priti Patel, in Parliament after Ms. Patel declared the government would schedule another flight to Rwanda.

Ms. Patel said Britain would not be deterred from sending asylum seekers to Africa. She called the opponents of the policy the “usual suspects,” adding, “We will not accept that we have no right to control our borders.”

That, in a nutshell, is the government’s message — one that Mr. Johnson and his fellow Brexiteers emphasized relentlessly during the long debate over Britain’s departure from the European Union. With the Conservatives facing embarrassing defeats in two Parliamentary elections on June 23, the prime minister hopes that “take back control” is still a politically resonant slogan.

On Wednesday, the headlines suggested it was. “Euro Court Grounds Jet to Rwanda,” said The Daily Mail, which added that Britain’s plan to end the asylum seekers’ perilous and illegal crossings of the English Channel had been stymied by “meddling judges in Strasbourg.” The Daily Express said, “Fury as Rwanda Flight Blocked.”

The policy has drawn fierce criticism from immigration and human-rights groups, not to mention religious leaders and even, according to British press reports, Prince Charles. Among the charges: It is inhumane, violates international agreements on refugees and sets a precedent for other nations to send migrants offshore.

Yet for all the criticism, legal experts said they understood Mr. Johnson’s frustration with the European court. British courts had refused to block the flight, based on the government’s pledge that it would return to Britain any migrants who had been relocated to Rwanda if the later judicial review struck down the policy.

“I’ve got some sympathy for the government on this one,” said Jonathan Sumption, a lawyer and former justice on Britain’s Supreme Court. “The issue is a very limited one: whether there was any risk of irreversible damage if the migrants spent a month in Rwanda. Three British courts have carefully analyzed the cases and found there was not a risk of irreversible damage.”

Still, Mr. Sumption said it was unlikely the dispute would prompt Britain to leave the European Convention. For one, such a move lacks the required parliamentary majority. For another, Britain’s ties are deep: British lawyers played a major role in drafting the convention. Churchill threw his political weight behind it. Even Mr. Johnson rejected a call to leave it before the 2016 Brexit referendum.

“Keep the European Convention, it’s a fine thing,” Mr. Johnson said at the time. “Get out of the E.U.”

Adding to the complication is Northern Ireland: Mr. Johnson insisted that his legislation overhauling the trade rules in the North was designed to preserve the Good Friday Agreement, which ended decades of sectarian violence there. But under the terms of that accord, Northern Ireland must remain subject to the European Convention.

If Britain left the convention, legal experts said, it could create a separate legal status for the North. But that would be politically arduous, given that Northern Ireland’s separate trade status has caused the tension between Brussels and London, and resulted in the legislation.

The European Union, in reactivating its legal case and filing additional claims against Britain, said Mr. Johnson had “no legal or political justification” to scuttle the trade rules. The British government had set out to “unilaterally break international law,” said the union’s chief negotiator, Maros Sefcovic.

That position is largely seconded by British legal experts, including Mr. Sumption, who described the government’s legal case as “utter rubbish.” But as with the Rwanda migrant flights, the legitimacy, or efficacy, of the policy may matter less than the political imperative of pushing it.

Addressing the tensions in Northern Ireland is particularly important for Mr. Johnson to appease hard-line Brexiteers in his party, several of whom turned on him after reports of illicit parties in Downing Street during the pandemic.

Mr. Johnson’s political vulnerability was underscored on Wednesday when his independent ethics adviser, Christopher Geidt, announced his resignation, one day after lawmakers questioned him about whether Mr. Johnson had violated the ministerial code by misleading Parliament over the parties.

Steve Baker, a leader of the pro-Brexit contingent in Parliament, said if Mr. Johnson failed in the Northern Ireland dispute, “the Euro-skeptics will lose faith, and when they lose faith, they will lose faith en bloc, and then he really will be in trouble.”

For some critics, however, the biggest danger is that Mr. Johnson’s moves will erode Britain’s well-established role as a champion of international law.

“When we now go around, saying to other states, ‘You’ve got to comply with this or that convention,’ they’ll say, ‘Well, you don’t,’” said Catherine Barnard, an expert on European law at Cambridge University.

Stephen Castle contributed reporting from London and Monika Pronczuk from Brussels.