London (dpa) - British Prime Minister Theresa May narrowly lost a key parliamentary vote on an amendment to her draft bill to assimilate EU legislation into English law, the first vote she has lost on Brexit.The amendment was carried by 309 votes to 305 votes late Wednesday, after about 10 rebel lawmakers from May‘s Conservative party had stated their intention to vote against the government.The rebels demanded that a final Brexit deal should be approved by parliament and enshrined in statute before the government makes any legal changes linked to leaving the European Union. They said the issue was a matter of upholding parliamentary sovereignty.