The British Supreme Court's ruling that Parliament must have a say in starting the process of leaving the European Union is unlikely to block it. A majority of lawmakers, even some who would rather see the country remain in the union, have shown a reluctance to challenge the result of the June referendum in which voters chose Brexit. But the court ruling at least restores some order to the process.

That is important, because many of the potentially costly consequences of withdrawing from the European Union were lost in the contentious and often demagogic referendum campaign, which focused largely on emotional objections to the free movement of people within the union. Much has changed since then, most notably the recognition — acknowledged in Prime Minister Theresa May's speech earlier this month — that Britain cannot pick and choose among the central tenets of the E.U. Closing Britain's doors to European citizens, it is now clear, means rejecting other facets of the union, like the elimination of barriers to trade and to the movement of goods, services and capital.

May had initially hoped to keep Parliament out of the separation process, partly because a majority of members had been against Brexit. But in a case brought by private citizens, a three-judge high court panel ruled in November that since it was Parliament that originally voted in 1972 to join the predecessor of the union, the government could not withdraw unless Parliament voted to do so.

That raised a storm of protest from Brexiteers and was appealed to the Supreme Court. But even before the decision, May had dampened some of the passions on both sides by pledging that she would send the agreement to both houses of Parliament for approval, but only after it was finished. The court blocked another potential problem for May by ruling that the government does not need separate approval from the regional legislatures of Wales, Northern Ireland and Scotland to invoke Article 50, which officially begins the process of separation.

The Supreme Court insisted that the issue before it had "nothing to do with whether we should exit the E.U., or the terms or the timetable." Yet by ruling that Parliament was sovereign in deciding whether to make a break, the court effectively undermined the argument of the Brexiteers that a referendum was the most democratic expression of the will of the people.

What members of Parliament do with their newly affirmed power is the next big question. Most likely, the stage is set for some fierce debates over the next two years, which will not make May's job of negotiating an exit easier. Given the stakes, what's important is that elected representatives of the British people have been restored to a process from which they had been foolishly excluded.

FROM AN EDITORIAL IN THE NEW YORK TIMES