B5b and F Branch
If you decide to conduct a war against a section of your own society you need soldiers. One area of fertile ground for finding people serious enough about 'anti-communism' to engage in such matters is amongst fascists.
It was amongst fascists that Vernon Kell - an early central figure in MI5 - found Maxwell Knight (or 'M'). Knight joined the British Fascisti in 1924, inspired by Mussolini, and determined to counter the growth of the Labour Party and the trade union movement, he quickly established himself as the organisation's Director of Intelligence. In that role Knight handled fascist cells in the trade union movement, engaged in 'counter espionage'. However his work came to the attention of Vernon Kell, he was soon recruited to carry out a similar role for MI5, organising against the General Strike in 1926 and, in the 1930s, he was put in charge of B5b, the unit in charge of countering political 'subversion'.
Amongst the subversive politics Knight found himself having to deal with were student pacifists (the Oxford Union motion, "this House will in no circumstances fight for its King and Country" was considered beyond the pale) as well as the British Communist Party and other left-wing organisations. Many of Knight's recruits were members of the main right-wing, fascistic organisations of the day, and he sent them into the left groups to counter subversion. Amongst his recruits were some whom the security services later had to turn on, such as Lord Haw Haw.
Knight also recruited left-wing agents. Tom Driberg - who would later be a charismatic Bevanite MP - was recruited in the 40s (while a communist party member) but was exposed and expelled from the party.
Increasingly, after the second world war, the security services saw that the labour movement itself could perhaps be its most effective enemy and, by infilitrating every left-of-centre organisation in the country, they could win a great victory against the left. F Branch particularly sought to recruit people from student unions, the Labour Party, Trade Unions, peace groups, etc. They were encouraged to sound as left-wing as possible in the hope that they might even be attractive to KGB recruitment agents. Quite how successful this was one day we may know. Just how many left activists were really working for the security services is a point of great interest to historians of this war on the left. Were some well-known figures in the labour movement really organising against it all along?
Well, certainly some were.
But we'll leave that little cliff-hanger there for the time being. The next section will consider the most bizarre chapter in all of this: the Wright and Wallace allegations about the Wilson plot and related events.