Britain's Prime Minister Theresa May attends a news conference during the EU Summit in Brussels, Belgium, March 9, 2017. [Photo/Agencies]

LONDON - British Prime Minister Theresa May cleared the final hurdle standing between her and the start of Brexit negotiations on Monday after parliament passed legislation giving her the power to start the EU exit process.

Members of the lower house of parliament voted to throw out changes to the bill made by the upper house earlier this month, after the government argued it needed freedom to operate without restriction to get a good deal.

Despite an attempt by the Liberal Democrats in the unelected upper chamber, the House of Lords, to re-introduce the conditions, the Lords also went on to approve the legislation unamended late on Monday.

"We are now on the threshold of the most important negotiation for our country in a generation," Brexit minister David Davis said in a statement.

"So we will trigger Article 50 by the end of this month as planned and deliver an outcome that works in the interests of the whole of the UK."

The bill will now be sent to the queen for symbolic approval which could be granted as early as Tuesday morning, leaving May ready to start a two-year negotiation period, as set out in Article 50 of the EU's Lisbon Treaty.

May's spokesman hinted on Tuesday, however, that she might do so closer to the end of the month.