Easily winning a crucial vote among lawmakers, Prime Minister Theresa May is well on her way to winning the parliamentary approval that Britain's Supreme Court said she needed before she could begin talks on ending more than four decades of European integration.
Wednesday's vote in the House of Commons will not be the final parliamentary verdict on May's plans, but with 498 lawmakers in favour and 114 against, it was emphatic enough to show that any subsequent efforts in Parliament to complicate, or slow, the path to withdrawal would probably be in vain.
The vote took place after two days of intense, sometimes agonised debate over a bill that, in just 137 words, sought permission to take one of the biggest decisions in British political life since it declared the war on Germany that became World War II.
The bill will still need to go to the House of Lords, where there are many opponents of British withdrawal, or Brexit. But invariably the unelected upper chamber gives way to elected colleagues in the House of Commons, providing there is a clear majority there.
Most analysts now expect the bill to complete its passage through Parliament in time for May to begin exit negotiations under Article 50 of the European Union's governing treaty by the end of March, as she has promised.
The debate before Wednesday's vote underlined the extraordinary pace of change in British politics during the past year.
Before last year's referendum on whether to quit the 28-nation bloc, more than half of the elected members of the British Parliament wanted to remain.
Wary of the opposition she might face, May tried to avoid going to Parliament before invoking Article 50 and agreed to do so only when instructed by the country's Supreme Court (See: No Brexit sans parliament nod, rules UK Supreme Court). In hindsight, that looks like a battle she need never have fought.
The 23 June plebiscite, in which around 52 per cent of those voting chose to leave, has transformed the Conservative Party, which had been split over a British exit, into an enthusiast for it.
Labour in crisis
Though the opposition Labour Party campaigned last year to remain, its leader, Jeremy Corbyn, is a lifelong critic of European integration and never seemed fully convinced about the pro-European case. On Wednesday, he instructed his lawmakers to vote to allow Brexit negotiations to start, an order that prompted a rebellion within his party.
Yet, that was limited to less than 50 people, because even Labour's most ardent proponents of remaining know that some of their usual supporters ignored their advice and voted to leave.
That has provoked an almost existential crisis for Labour, one hinted at on Tuesday when Keir Starmer, the Labour politician responsible for dealing with the British exit, noted that two-thirds of Labour lawmakers represent constituencies that voted to leave in the referendum.
''This is obviously a difficult decision,'' he said. ''I wish the result had gone the other way - I campaigned passionately for that - but as democrats, we in the Labour Party have to accept the result,'' Starmer said. ''It follows that the prime minister should not be blocked from starting the Article 50 negotiations.''
That stance has left the Scottish National Party as the clearest source of opposition, but one with insufficient numbers to change the parliamentary arithmetic. On Wednesday night, Stephen Gethins, who speaks for the party on European issues, described the vote as ''a devastating act of sabotage on Scotland's economy and our very social fabric''.
David Davis, the minister in charge of negotiating the British exit, told lawmakers that ''a point of no return already passed''. Britons, he said, were asked ''whether they wanted to leave the European Union, and they decided they did.''
''At the core of this bill lies a very simple question: Do we trust the people or not?'' Davis said.
Costs of Brexit
Kenneth Clarke, a veteran Conservative lawmaker and former Chancellor of the Exchequer, said before the vote that he would vote against invoking Article 50. ''I personally shall be voting with my conscience content, and when we see what unfolds hereafter as we leave the European Union, I hope that the consciences of other members of Parliament will remain equally content,'' he said.
All the same, it looks increasingly likely that winning British parliamentary approval may be the least of May's problems.
Before Parliament's Northern Ireland affairs select committee, a former senior European Union customs official, Michael Lux, warned of the likelihood of checks at the border between Northern Ireland and Ireland, something May and Northern Ireland officials dearly want to avoid.
Speaking to a separate committee, Ivan Rogers, who resigned recently as Britain's permanent representative to the European Union, said the exit talks would be on a ''humongous'' scale and would be conducted with ''name-calling'' and in an ''extremely feisty atmosphere''.
Rogers left his post after his assessment of the complexity of leaving the bloc fell out of step with the government's, prompting him to send a resignation letter urging his former colleagues to ''challenge ill-founded arguments and muddled thinking, and that you will never be afraid to speak the truth to those in power.''
He has said that British politicians in charge of the exit are not grappling with the true costs and enormous scale of the task. European Union officials were suggesting that Britain should pay from $43 billion to $65 billion to resolve its outstanding liabilities before leaving, and reaching a trade deal between Britain and the bloc could take until the mid-2020s, he said.
''It's a negotiation on the scale that we haven't experienced ever, certainly not since the Second World War,'' Rogers said.