Members of Parliament on Monday night in the elected chamber rejected both amendments to the Brexit bill put forward last week in the House of Lords, Xinhua news agency reported.
By 335 votes to 287, MPs rejected the amendment guaranteeing the rights of 3.2 million European nationals to remain in Britain after Brexit.
Minutes later, the Commons voted by 331 to 286 to reject the second amendment to guarantee a meaningful vote by the Parliament before a final Brexit deal is agreed.
Ministers argued that support for either amendment would have tied the hands of Britain's negotiations with Brussels.
The focus now switches to the House of Lords, who will now have to vote on the unamended Brexit bill.
As soon as the process is completed in the Houses of Parliament, a royal assent will be formally given by Queen Elizabeth II to give May full authority to finally trigger Brexit.