On 28 March 1938, Porter was appointed Lord of Appeal in Ordinary, in succession to the new Lord Chancellor, Lord Maugham, without having previously served as a Lord Justice of Appeal. He was created a life peer with the title Baron Porter, of Longfield in the County of Tyrone.
On 28 March 1938, Porter assumed the position of Lord of Appeal in Ordinary, succeeding Lord Maugham as the new head of the judiciary without prior experience as a Lord Justice of Appeal. He was subsequently elevated to life peer status with the title Baron Porter, of Longfield in the County of Tyrone.