London: Theresa May has pulled the trigger on one of the most significant political experiments in Britain's modern history - leaving the European Union, describing the moment as a character-defining "turning point" in the nation's history.
The British Prime Minister warned MPs that there was no going back and that there would be "consequences" for leaving the single market but struck a conciliatory tone talking of a future "deep and special relationship with Europe", while pleading for national unity at home.
A formal letter signed by the British Prime Minister was handed to European Council president Donald Tusk in Brussels just before Mrs May's statement to the British Parliament in Westminster. It triggered Article 50, setting up two years of negotiation of the terms of Britain's exit.
"There is no reason to pretend that this is a happy day, neither in Brussels nor in London," Mr Tusk said, waving Mrs May's six-page letter.
"After all, most Europeans, including almost half the British voters wish that we would stay together, not drift apart," he said.
"As for me, I will not pretend that I am happy today.
"In essence this is about damage control, our goal is clear - to minimise the cost for the EU citizens, businesses and member states," he said.
"What can I add to this? We already miss you," he concluded, in a statement to the media at which he took no questions. Mr Tusk will release the negotiating guidelines on Friday.
Mrs May said she wanted those talks concluded by the two-year period set out in the Treaty of Lisbon, with a phasing-in of Britain's exit for a period after.
"This is an historic moment from which there can be no turning back," the Prime Minister told MPs.
She made a rousing plea for unity, fending off pressure from the Scottish National Party (SNP) to hold a second independence referendum because of the Brexit vote, and said she hoped Britain would emerge from Brexit "fairer", "stronger" and "more outward looking than before".
"We understand that there will be consequences for the UK of leaving the EU," Mrs May said.
"We know that we will lose influence over the rules that affect the European economy. We know that UK companies that trade with the EU will have to align with rules agreed by institutions of which we are no longer a part, just as we do in other overseas markets. We accept that.
"However, we approach these talks constructively, respectfully, and in a spirit of sincere co-operation.
"There should be no reason why we should not agree a new deep and special partnership between the UK and the EU that works for us all."
Mrs May said it was time for the country to come together and said she envisioned a Britain "no longer defined by the vote we cast but by our determination to make a success of the result".
The Prime Minister is staring down a fresh push from the SNP to hold a second referendum for independence.
Sixty-two per cent of Scots voted Remain and Britain's status as an EU member was a key factor in the first referendum, with the British government pointing out that Scotland would stand to lose access to the single market if it left the United Kingdom. The Scottish parliament on Tuesday voted to call for a second independence referendum.
The SNP's Angus Robertson warned Mrs May that she would make the break-up of the kingdom "inevitable" if she didn't comply with Holyrood's wishes.
"The Prime Minister says that she thinks that Brexit will bring unity to the United Kingdom. It will not - on this issue it is not a United Kingdom," he said.
"And the Prime Minister needs to respect the differences across the nations of the United Kingdom. If she does not, if she remains intransigent and if she denies Scotland a choice in our future, she will make Scottish independence inevitable," he added, to applause and cheers from his colleagues.
Mrs May said her own electorate had voted to Remain. "The point is that we are one United Kingdom and it was a vote of the whole United Kingdom," she said.
Labour Party leader Jeremy Corbyn accused Mrs May of wanting to turn Britain into a "low-wage tax haven" after Brexit. In her speech, Mrs May stressed that she wanted to protect workers' rights.
Both Britain and the EU have signalled they want to resolve as an early priority the status of Britons living in the EU and Europeans living in Britain.
Conservative MP Matt Warman represents an electorate where three-quarters of voters supported Brexit.
In Parliament he described the day as a "watershed moment" for Britain's "control of immigration and sovereignty" but "also for listening to the views of people who were forgotten for far too long."
