SPOOKS intercepted Labour Party chairman Harold Laski’s private correspondence during the 1930s and ’40s in a bid to expose his links to the Communist Party.

Files released today show that MI5 intercepted Laski’s private letters from 1930 until his death in 1950 aged 56 — despite an MI5 report to the Home Office as early as 1930 saying he was “not a communist.”

Laski was a prominent Labour leftwinger, who chaired the party during its landslide election victory in 1945, having moved towards Marxism during the extreme economic hardship that engulfed Britain in the 1930s.

The newly disclosed files include a letter he wrote to Communist Party general secretary Harry Pollitt in 1936 in which he declared: “We want the average man to understand that Soviet communism is the triumph of all that means hope for civilisation.”

Notes from a St Pancras People’s Front propaganda committee meeting were also included on Laski’s file in which he told the audience it was of “vital importance to form a united front of the Labour and Communist parties.”

However he later apparently moved away from the Communist Party, writing to Pollitt in 1944 to complain about the “labyrinthine dishonesties” of the CP.