He was interned during the Second World War because of his fascist associations and appealed to the Judicial Committee of the House of Lords against his detention.
In the leading case of Liversidge v. Anderson the Law Lords declined to interfere with ministerial discretion on matters of national security and thus refused to review his detention.
[2] He returned to London and during the 1923 United Kingdom general election he worked for Clement Attlee in the Limehouse constituency, where he met John Beckett.
[2] Shocked by conditions in Germany, Greene formed the idea that Britain should co-operate with Nazi officials in order to facilitate the emigration of as many threatened Germans as possible.
Greene tried to connect with anyone who was opposed to war, including fascists, and later joined the British People's Party (BPP), becoming its treasurer.
At the same time Vernon Kell was calling for action against the BPP, in particular for Greene and Beckett's internment under Defence Regulation 18B.
[6] The "Reasons for Order" cited Greene's membership of the BPP and the British Council for Christian Settlement in Europe, the content of his speeches, his association with Beckett, and his communications with the German government.
[10] The Lord Chancellor's Department was advised and Greene was informed on 10 October of the intention to remove him as a JP, though he was offered the face-saving alternative of resignation.
[11] Greene's brother Edward sought legal advice from Oswald Hickson, who had been active in internment cases from a liberal rather than a fascist standpoint.
Hickson wrote to the Advisory Committee to protest that the "Reasons for Order" gave no particulars of the persons who had made the allegations against Greene.
[12] The court dismissed Greene's application, but expressed concern about the technical errors in the drafting of the detention order and criticised the Home Secretary.
The committee rejected Kurtz's allegations, as having been discredited, and accepted Greene's undertaking not to hinder the war effort and to avoid contact with Beckett and Hastings Russell, 12th Duke of Bedford.