An Independent Labour Party Member of Parliament from 1907 to 1910, Grayson is most notable for his sensational by-election victory at Colne Valley, and unexplained disappearance in 1920.

[1] Grayson joined the Independent Labour Party (ILP) and toured the country giving lectures, becoming a well-known orator despite having a stammer.

After losing his seat in the January 1910 general election, and failing even to retain his deposit when standing for Kennington in December 1910, he continued his lecture tours but suffered a mental breakdown in 1913 and in August 1914 was declared bankrupt with debts of £496.

[4] Grayson later alienated many of his left-wing colleagues by backing Britain's entry into World War I and turning his oratorical skills to recruiting soldiers.

[6] In 1918, Sir Basil Thomson, head of the Special Branch, asked Maundy Gregory to spy on Grayson, suspecting him of working as an agent for the new communist government in Russia or for the Irish Republican Army.

[8] Biographer David Clark believes that, having alienated both the socialists and the trade unions, Grayson had entered into blackmail in order to fund his lavish lifestyle.

[4] Journalist Donald McCormick claims that artist George Flemwell had been painting a picture of the Thames when he saw Grayson passing him in an electric canoe, along with Maundy Gregory.

[9] Flemwell further observed the two men entering a house (Number 6, The Island, Thames Ditton) on the river bank on 28 September 1920.