In a special Saturday sitting, MPs voted by 322 to 306 in favour an amendment withholding approval of his Brexit deal until legislation to implement it is in place.
However the Prime Minister was not ‘dismayed’ by the result and said he will not negotiate a new Brexit delay with the EU despite losing the key vote.
The amendment tabled by former Conservative Cabinet minister Sir Oliver Letwin was intended to force him to comply with the so-called Benn Act requiring him to seek a Brexit extension.
Boris Johnson insisted that he remained committed to taking Britain out of the EU by October 31 and would do “all he can to get Brexit done”.
Speaking in parliament Boris Johnson said: "I will not negotiate a delay with the EU, neither does the law compel me to do so.”
He added: “The best thing for the UK and Europe is to leave with this deal on October 31.
“Further delay would be bad for the country and democracy.”
The legislation will now be introduced to the House of Commons next week.