By Francis Beckett
Routledge, £16.99

All political lives may end in failure but it is hard to think of another British MP who torpedoed his own promising career quite as spectacularly as John Beckett. When he first entered parliament in 1924, Beckett was, at 30, Labour's youngest MP, with a growing reputation as an orator.

The member for Gateshead was a champion of the unemployed and a notorious ladies' man. Tipped for high office, he was also a theatre manager who mixed with the stars of the London stage. He struck a glamorous, dangerous, if slightly self-absorbed figure in a Labour Party weighed down by dull compromise.

However, by the mid-1930s, this passionate left-winger had become disillusioned with the inability of parliamentary socialism to deliver for the working man and was increasingly attracted by the authoritarian politics of Mussolini.

In 1934, after a number of his theatrical productions had bombed, he was offered a salary by Oswald Mosley, the leader of the British Union of Fascists, and completed the extraordinary journey from the respectable left to the extreme right.

That he joined Mosley's Blackshirts is made all the more remarkable by the fact that his own mother was Jewish. Eva Solomon was the daughter of Mark Solomon and Jessy Isaacs, which made one of the most prominent figures in British fascism halachically Jewish himself.

What makes this story all the more poignant is that it is told by Beckett's own son, Francis. And nor is it the first time he has turned to the subject in print. His 1999 book, The Rebel Without a Cause, was a straight biography. This is something different. It is part political history, part memoir: an attempt to come to terms with the horror of growing up with a fascist as a father.

It is, above all, a very sad story. Although Becket Jnr refuses to categorise him as a "bad man", the John Beckett was see here is vain, selfish and driven by a warped idealism that damages all around him.

And yet, there is a respect here, too, for the complexity of John Beckett's mangled political personality. There is a passage in the chapter on the politician's fall from grace that captures the author's mixture of love and disdain: "He was shocked by the people who were attracted to fascism because it enabled them to strut about self-importantly in a uniform. He does not seem to have realised that all this was an intrinsic part of the creed he had embraced. The fascist – for that is what we must call him – was intelligent, sincere, noisy and very human."

Francis Beckett does not appear to dislike his father, indeed he is touchingly protective of the man (though never his politics). He reserves his hatred for the man assigned to monitor his activities for MI5, G. R. (Graham) Mitchell. Everything John Beckett wrote was read by Mitchell, including his love letters to Anne, Francis's mother. In 1943, Mitchell wrote a paper recommending that Beckett should remain in prison despite serious health problems and little evidence of being a genuine national security risk. "I find it impossible to read Mitchell's paper without feeling that I have touched something unclean," writes a son clearly still viscerally upset by the treatment of his father.

Fascist in the Family makes for fascinating reading at a time of economic and political uncertainty when many on the left share the young John Beckett's frustrations at the inability of social democracy to deliver for working people.

The antisemitism that can so easily flow from such feelings of impotence is still with us. Francis Beckett has provided a unique insight into what happens when a man, apparently devoted to the good of the common people, turns to racism and hatred to pursue his personal political vision.

Martin Bright is a former political editor of the JC