The British government will send a letter to the European Commission on March 29, saying the country intends to leave the European Union.

Britain's Prime Minister Theresa May speaks at the Conservative Party's Spring Forum in Cardiff, Wales, March 17, 2017.??[Photo/Agencies]

A spokesman for British Prime Minister Theresa May told reporters the letter will trigger Article 50 of the Treaty of Lisbon, and a maximum of two years of negotiations on the way to Britain's departure from the EU.

Reporters were told that the UK's permanent representative to the EU, Sir Tim Barrow, had a discussion with representatives from the office of Donald Tusk, the president of the European Commission, in which he informed them about the letter and when it might arrive.

"There will be a letter, she will notify President Tusk in writing, and the prime minister has already confirmed she will give a statement to parliament as well," he said. "More details will be given in due course."

The letter will start an unprecedented process, the outcome of which no one can predict. It was preceded by a referendum in the UK in June, through which voters chose to leave the EU by 52 percent to 48 percent.

May was expected to announce the date on which she would send the letter last week, but she appeared to have been surprised by a call from Nicola Sturgeon, the Scottish first minister, for a referendum on Scottish independence, leading to speculation that May did not wish to appear cavalier about the future of the union.

Tusk is expected to take 48 hours to reply to May with an approximate timetable for negotiations. The first date on the agenda is likely to be an extraordinary summit involving the 27 countries that will remain in the EU. This is likely to take place before summer.

The negotiations will encompass a multitude of issues, including the UK's payment of an exit fee for costs it has already committed itself to. Reports have suggested the fee could be as high as 60 billion euros ($64.5 billion).

Major issues will also include freedom of movement, the rights of EU nationals in the UK and UK nationals in EU member states, Britain's access to the European Single Market, security, and environment co-operation.

At the end of the process, May has said the UK Parliament will have a chance to vote on the Brexit deal, as will all the parliaments of EU member states.

May, who was visiting Swansea on Monday, intended to visit Northern Ireland and Scotland before the formal notification letter is sent, Downing Street said.

The writer is a freelancer for China Daily UK.