LONDON — Protesting Britain’s plans to leave the European Union, Scotland’s leader, Nicola Sturgeon, called on Monday for a referendum on Scottish independence as early as next year.

The announcement was not unexpected, but it reflected the stark divisions in Britain as the government prepares to start the official process to exit the 28-nation bloc. Citing the fact that most Scottish voters had opposed a British exit in last year’s referendum — 62 percent voted in favor of staying in the European Union, compared with 48 percent in Britain overall — Sturgeon said that London had failed to address Scotland’s desire to remain in the single market after Britain leaves.

“Not only is there no UK-wide agreement on the way ahead, but the UK government has not moved even an inch in pursuit of compromise and agreement,’’ Sturgeon said in a speech in Edinburgh. “Our efforts at compromise have instead been met with a brick wall of intransigence.’’

Scotland rejected independence from Britain in a closely watched vote in September 2014, and public opinion on the issue remains deeply divided. For Scotland to hold another legally binding referendum, the British Parliament would have to give its approval, as would the Scottish Parliament.

Sturgeon’s comments came hours before the British Parliament cleared the way for Prime Minister Theresa May to invoke Article 50, the formal procedure that sets off a two-year negotiation with the 27 other member states of the European Union.

Sturgeon said her preferred time frame for a new vote would be in the autumn of 2018 or the spring of 2019, when the terms of a British exit from the bloc would be clearer.

She said she would ask Scotland’s devolved Legislature in Edinburgh to request approval from the British Parliament for the new referendum, known as a Section 30 order, next week.

May has accused Sturgeon and her Scottish National Party, which dominates politics in Scotland, of having an “obsession’’ with independence. But officials say it would be politically difficult for May to refuse a new referendum outright.

The prime minister’s office said in a statement on Monday that it had been “working closely’’ with Scotland, Northern Ireland, and Wales, “recognizing the many areas of common ground’’ on issues like fighting terrorism and protecting workers’ rights.

“The evidence clearly shows that a majority of people in Scotland do not want a second independence referendum,’’ the statement said.

“Another referendum would be divisive and cause huge economic uncertainty at the worst possible time,’’ it said. “The Scottish government should focus on delivering good government and public services for the people in Scotland.’’

Sturgeon’s party won the 2015 election in Scotland on a manifesto that left open the door for another independence referendum should circumstances “materially change,’’ and she had cited a so-called Brexit — then considered highly unlikely — as an example of such a change.

The real fight might be over timing: London, officials say, would prefer that Scotland put off another vote until after Britain has left the European Union, betting that voters will feel less confident about leaving once they have been pulled out of the bloc.

Sturgeon emphasized that Scotland should not be withdrawn from Europe against the will of its people. She also pointed to the weakness of the opposition Labour Party, citing predictions of a Conservative Party government in London “until 2030 or beyond.’’

Since the June referendum on Britain’s future in Europe, Sturgeon has argued that Scotland should be given a special status.

So far, May has ruled out any concessions. On Monday, Sturgeon said there could be room for compromise if the prime minister were to offer a deal for Scotland, but she noted that no options had yet been offered.

In London on Monday, Parliament gave May the power to formally leave the EU.

The House of Commons approved the bill weeks ago, but the 800-strong House of Lords fought to amend it, inserting a promise that EU citizens living in the UK will be allowed to remain after Britain pulls out of the bloc.

The Lords also added a demand that Parliament get a ‘‘meaningful’’ vote on the final deal between Britain and the remaining 27 EU nations.