Jerome Bannigan (d. 1970), aka George Andrew McMahon, was an Irish "fraudster," and "fanaticist," and would-be assassin of King Edward VIII. On 16 July 1936 he pulled a gun as the king was riding through Hyde Park after leaving an army parade during the Colour ceremony. Police and bystanders acted and managed to subdue McMahon after a struggle, and an unfired revolver fell near the feet of the King's carriage as he continued safely down Constitution Hill. McMahon, denounced in 1940 as a Nazi sympathizer, claimed he had been angered by the Home Secretary's alleged failure to respond to his reports of a plot to kill the King and later claimed to have been working with MI5.
McMahon had earlier attempted to provide questionable evidence of Irish and Republican plots against the British government, including a claim of plans to ship weapons to the Irish Free State in 1935 as well as reports of Italian agents operating from the Italian embassy, before publishing anti-semitic literature and other letters to The Daily Worker.
Although under the attention of the Security Service, his warnings against a supposed assassination plot by Communists were ignored and, two days later, he managed to throw a loaded revolver at the King during a parade before being arrested by the Metropolitan Police on 16 July 1936.
McMahon was subsequently sentenced to 12 months imprisonment; shortly after his release, however, he continued his subversive activities. During November 1939, he claimed in a letter to have had a personal audience with senior Nazi official Julius Streicher the previous year, and offered information from that meeting to British authorities.
The following year, he began sending anti-Semitic letters (which included an attack on Minister of War Leslie Hore-Belisha) using War Office letterheads on the pretext of official government communications. McMahon continued to be under the surveillance of the Security Service between 1945 and 1951, and they intercepted several letters including one to Oswald Mosley.