The Brexit bill has been passed by Parliament after peers' objections over EU residency rights were overturned.
The bill will now become law without any assurances on the future of EU nationals working in the UK.
Last week the House of Lords voted to guarantee the rights of EU nationals living and working in the UK in an amendment to the Brexit bill and accused the government of treating the employees like "bargaining chips".
But this amendment has not been retained in the final bill, which means the rights of EU nationals working in the UK remains uncertain as Theresa May prepares to trigger Article 50 and the start of two years of Brexit negotiations.
The original EU Withdrawal Bill was passed last night after peers voted by 274 to 118 not to challenge the government.
Brexit secretary David Davis said: "We are now on the threshold of the most important negotiation for our country in a generation."