Kirsty Wigglesworth, AP
FILE - This is a Wednesday, Nov. 2, 2016 file photo of Britain's Prime Minister Theresa May speaks during a press statement with Colombia's President Juan Manuel Santos at 10 Downing Street in London. Britain’s High Court brought government plans for leaving the European Union screeching to a halt Thursday, Nov. 3, 2016 ruling that the prime minister can’t trigger the U.K.'s exit from the bloc without approval from Parliament. (AP Photo/Kirsty Wigglesworth, pool, File)

LONDON — British Prime Minister Theresa May sought Friday to reassure European Union leaders that her timetable for Britain to leave the EU remains intact despite a court ruling requiring lawmakers to have more of a say in the next step towards Brexit.

She telephoned Jean-Claude Juncker, the EU's top official, and German Chancellor Angela Merkel to spread the word that her plan is still to start the process to remove Britain from the EU by the end of March. Officials say she will also call French President Francois Hollande and European Council President Donald Tusk later in the day.

European Commission President Juncker told May that he respects Britain's constitutional order and that the timing of Brexit is in the hands of British authorities, EU spokeswoman Mina Andreeva said after the brief call.

The calls came a day after a High Court ruling that the government needs Parliament's approval before invoking Article 50 of the EU treaty, which formally begins a two-year countdown to Britain's exit. The decision by the three-man court has the potential to delay that process.

The government is appealing the ruling at the Supreme Court with a hearing expected next month. If the country's highest court rules against the government, Parliament will become directly involved in discussions over how the Brexit process begins.

A number of lawmakers from opposition parties, in particular, have made clear they want assurances from the government that it won't be going for a so-called "hard Brexit" that will see Britain leave the European single market of more than 500 million people.

The court decision on Thursday has stoked speculation that May will look to call an early general election in the spring of next year. Her Conservative Party stands to win an overwhelming majority, according to a run of opinion polls.

A number of pro-Brexit newspapers reacted with venomous anger to the court decision, arguing that it goes against the will of the British people stemming from the June 23 referendum and slows down the unchecked arrival of immigrants from other EU countries into Britain.

The Daily Mail tabloid front page characterized the three High Court judges as "Enemies of the People." Its editorial complained that "three members of an out of touch clique" were willing to frustrate the wishes of the more than 17 million people who voted in favor of leaving the 28-nation EU bloc.

The more measured Daily Telegraph headlined its front page: "The judges versus the people," and carried a front-page column by UK Independence Party interim leader Nigel Farage saying the court ruling means that "a great betrayal is underway."