Most immediately, the ruling raised questions about the future of Mr. Johnson, who was already reeling after multiple defeats in Parliament, a rebellion in his own Conservative Party, and new questions about his ties to a young businesswoman when he was mayor of London.
Speaking before a meeting with President Trump at the United Nations, Mr. Johnson said he disagreed “profoundly” with the ruling and would forge ahead with his plans to leave the bloc. But he added, “Let’s be absolutely clear, we respect the judiciary in our country, we respect the court.”
Mr. Trump, who has cultivated Mr. Johnson as a like-minded populist, played down the significance of the decision. Noting that he had lost several cases in the United States Supreme Court before gaining some victories, Mr. Trump said, “For him, it’s another day in the office.”
Still, the debate over whether and how to leave the European Union, which voters agreed to do in a June 2016 referendum, proved the undoing of Mr. Johnson’s two predecessors as divided Britons took to the street to protest. Now, he faces an uncertain future as he ventures back into Parliament.
Brexit Turmoil Intensifies as Court Rebukes Boris Johnson – The New York Times