MPs have given British Prime Minister Theresa May their authority to formally begin Brexit in an overwhelming House of Commons vote.

The European Union (Notification of Withdrawal Bill) was approved at third reading, its final Commons stage, after Labour leader Jeremy Corbyn ordered his MPs to back it.

But Mr Corbyn was unable to prevent the resignation of senior shadow cabinet minister Clive Lewis, who quit the frontbench to vote against the Bill in defiance of a three-line whip.

The legislation, which will give Mrs May the authority to begin exit talks under Article 50 of the EU treaties, was passed by 494 votes to 122, a majority of 372.

But it will now have to pass through the House of Lords before Mrs May can invoke Article 50, which she has promised to do by April.

A total of 52 MPs rebelled against Mr Corbyn's orders and voted against triggering Article 50, up from the 47 who opposed the legislation at second reading last week.

Former chancellor Ken Clarke was again the only Conservative to vote against the Bill.

The simple two clause Bill was passed without any changes after around 40 hours of debate in the Commons.

The government also saw off the threat of a significant Tory rebellion over the rights of EU citizens already in the UK.

Just three Tory backbenchers - Mr Clarke, Tania Mathias and Andrew Tyrie - rebelled to back a bid to make ministers unilaterally guarantee EU nationals' rights.

The amendment put forward by Labour's Harriet Harman was defeated by 332 votes to 290, majority 42, after Home Secretary Amber Rudd sent a letter to Conservative MPs offering them assurances over the issue.

The government has said it will treat EU nationals' status as a priority in Brexit negotiations and seek to strike a reciprocal agreement to also protect the rights of British expats in Europe as soon as possible.