In 1920, Shepherd became Labour Party District Organiser for the London and Southern area.

This meant he was in charge of the Labour Party agents nationwide at the landslide election victory which brought Clement Attlee to No.

The Member of parliament for Blackburn was the senior Labour Party politician Sir Stafford Cripps, a post war Chancellor of the Exchequer and this position must have been important to his career in The Labour Party.

When Sir Winston Churchill requested that Clement Attlee and the Labour Party enter into a wartime coalition, he negotiated the terms of the coalition agreement with George Shepherd.

On 28 June 1946 he was raised to the peerage as Baron Shepherd, of Spalding in the County of Lincoln,[2] becoming one of the few Labour peers in the House of Lords.