LONDON, Jan. 23 (Xinhua) -- British government's Brexit bill became law Thursday after Queen Elizabeth II gave it her royal assent, paving the way for Britain's exit from the European Union (EU) on Jan. 31.

Under the government of former prime minister Theresa May, the withdrawal bill went through a bumpy ride in the parliament. The journey became smoother after Boris Johnson's landslide victory in a snap general election in December.

Armed with a 80-seat majority in the House of Commons (lower house), the bill was able to beat all opposition and passed its final legislative stage in the House of Lords (upper house) Wednesday after peers gave it their approval.

Spelling out arrangements for Britain's departure from the union, the approved bill will be signed at a ceremony in Brussels Friday by Ursula von der Leyen, president of the European Commission, and Charles Michel, president of the European Council.

Negotiations between Britain and the EU will soon start on a future trade deal. Johnson has repeatedly insisted that he will not extend the transition period. Last month, the House of Commons passed his Brexit bill, where he added a clause to rule out any extension beyond Dec. 31, 2020.

During a speech in London earlier this month, von der Leyen warned that the two sides need more time to reach a deal.

"Without an extension of the transition period beyond 2020, you cannot expect to agree on every single aspect of our new partnership," she said.