British lawmakers on Wednesday voted 461 in favor of supporting Theresa May's Brexit timetable, while 89 voted against the motion.

The Prime Minister now has the Parliament's backing to trigger Article 50 of the EU's Lisbon Treaty, formally launching Brexit proceedings, by March 31, 2017.

The vote was pushed by the opposition Labour Party, which tried to force May to publish more details of her strategy before invoking Article 50. 

However, May turned the tables on Labour by publishing an amendment effectively accepting the motion, while also proposing that Wednesday's debate should also be on whether lawmakers "respect the wishes" of the British people to leave the EU.

Parliament voted in favor of the Labour motion calling on the government to set out its Brexit plan by 448 to 75. 

"The focus is now where it should be: on the terms upon which we exit the EU," Labour's Brexit spokesman Keir Starmer said in a statement released Wednesday ahead of the vote.

"Labour have consistently said that we will not frustrate or delay the process of triggering Article 50. Therefore Labour will accept the government's amendment," Starmer said.

Government minister David Lidington warned on Wednesday that any lawmaker voting against the motion would "be seeking to thwart the outcome of the referendum in the most profoundly undemocratic manner."

The vote, however, is not binding and the government is still fighting a legal challenge in the Supreme Court that parliament should have the final say on triggering the UK's withdrawal process from the European Union.

May pressured to show Brexit hand

May has come under increasing pressure from lawmakers, businesses and investors over a lack of insight into the government's Brexit strategy. She has repeatedly said that prematurely revealing her hand would undermine the UK's position ahead of the negotiations.

Lawmakers welcomed May's decision to offer parliamentary scrutiny of her Brexit plan. However, some MPs have expressed concern that May will offer little beyond stock catchphrases and pledges to get "the best possible deal."

"The government's commitment to publishing a Brexit plan is good news but the devil will be in the detail," James McGrory, an executive director of the Open Britain campaign lobbying for a so-called "soft" Brexit, said. "The plan they bring before parliament should be substantive and it should be given proper time for debate."

However, Labour lawmaker Ben Bradshaw has labeled May's amendment a "trap." 

"I will not vote today to invoke Article 50 by March when we still have no idea what sort of Brexit the government will pursue," he wrote on Twitter.

A spokesman for the PM said Wednesday's parliamentary vote will not affect the government's case currently being heard by the Supreme Court over who has the right to trigger Article 50, calling it a "separate issue."

"The court knows a motion may be approved in the House of Commons today," David Pannick, the lawyer leading the challenge to the government's position told the Supreme Court on Wednesday.

"I want to be very clear about this. Our submission is that a motion in parliament does not affect, cannot affect, the legal issues in this case," Pannick said.

Brexit minister: EU parliament may vote on final deal

David Davis, Britain's Brexit minister, said on Wednesday that the British Parliament may not get to vote at all on the country's final Brexit deal.

In a parliamentary debate Wednesday, Davis said: "If the European Parliament has a vote, it is inconceivable this house doesn't - simple as that."

However, he said such an outcome would not reverse the fact that Britain was leaving the EU.

Davis also said that, with at least 15 elections scheduled to take place across the bloc during the two-year Brexit negotiation period, the backdrop to Britain's withdrawal could make "a challenging climate" for talks.

Man arrested for racist messages to Brexit opponent

British police on Wednesday said they had arrested a man on suspicion of sending racist messages to a businesswoman spearheading the legal challenge to Britain's divorce from the EU.

Gina Miller, who was born in Guyana, revealed to the BBC after an initial High Court hearing that she had been target of racist trolls on the Internet. The abusive remarks included jibes that "I should be beheaded, gang-raped, I'm not even human, I'm a primate, I belong in a kitchen - that's the nicest of them," she said.

London's Metropolitan Police revealed they had detained a 55-year-old man from Wiltshire, south-west England, for making online threats dating back to November 3, the day following the ruling that May could not trigger Article 50 without consulting lawmakers in parliament.

Police said the man was suspected of sending racially aggravated malicious communications. He was later released on bail.

dm/se (AP, Reuters, dpa)