LONDON — Britain’s unelected House of Lords handed the government a stinging — though likely temporary — defeat Wednesday on its plans to leave the European Union, resolving that EU citizens should be promised the right to stay in the United Kingdom after it quits the bloc.
By a vote of 358 to 256, Parliament’s upper chamber inserted a clause protecting EU nationals’ status into a bill authorizing the government to begin EU exit talks.
The Labour Party’s Brexit spokeswoman in the Lords, Dianne Hayter, said Europeans living in Britain ‘‘need to know now, not in two years’ time or even 12 months’ time’’ what their rights are.
‘‘You can’t do negotiations with people’s futures. They’re too precious to be used as bargaining chips,’’ Hayter said.
The promise may not turn out to be binding on the government, however. The change must go to a vote in the elected House of Commons, where there is a good chance it will be rejected since Prime Minister Teresa May’s Conservative Party has a majority in the lower chamber.
By leaving the European Union, Britain will be withdrawing from the bloc’s policy of free movement, which allows citizens of the bloc’s 28 member states to live and work in any of the others. That leaves 3 million EU nationals in Britain, and 1 million Britons in other member countries, uncertain whether they will be able to stay in their jobs and homes once Britain reasserts control over EU immigration.
The government has said repeatedly that it plans to guarantee the right of EU citizens to remain in Britain, as long as UK nationals living elsewhere in the bloc get the same right. Critics accuse the government of treating people as bargaining chips in the divorce negotiations.