The House the Commons voted Wednesday to allow the PM to begin the Brexit process, Joinfo.com reports with reference to the BBC.
MPs backed the European Union Bill by 498 votes to 114 on Wednesday night, with 47 Labour rebels voting against.
The bill will now face more debate before it can become law.
MPs will discuss the bill in more detail next week when it reaches the committee stage in the Commons, and Labour has vowed to force through amendments.
Hundreds of amendments have already been tabled for debate between Monday and Wednesday, with objectives set out in the government’s strategy expected to attract more.
Shadow cabinet members Rachael Maskell and Dawn Butler quit the party’s front bench shortly before Wednesday evening’s vote, and in total, 13 Labour frontbenchers voted against their own party position which was to support the bill.
Speaking on BBC Radio 4’s Today programme, shadow chancellor John McDonnell said other parties had also been divided on the issue, with two of the Liberal Democrats’ nine MPs abstaining despite orders to oppose the bill.
Mr McDonnell said a decision on whether frontbench rebels could remain in their jobs would be taken “in due course”, and that the atmosphere in his party was “one of mutual respect”, with determination to oppose a “reckless Brexit”.
He said Labour “may look divided” but would unite after the government triggers official negotiations under Article 50 of the Lisbon Treaty while “the Tory Party will split apart”.
The Brexit bill was published last week, after the Supreme Court decided MPs and peers must have a say before Article 50 could be triggered.
It rejected the government’s argument that Mrs May had sufficient powers to trigger Brexit without consulting Parliament.
Iain Watson, BBC political correspondent, said a “sizeable” Labour rebellion could grow further if amendments were not passed.