Police deployed 24 undercover officers to infiltrate a small leftwing political party over a 37-year period, the Guardian can reveal.
The police spies infiltrated the Socialist Workers party (SWP) almost continuously between 1970 and 2007, often with more than one undercover officer embedded within the party.
Four of them deceived women into sexual relationships while using their fake identities. One spy met one of his wives during his deployment and had a child with her.
About one-third of the total number of undercover officers embedded in political organisations that have so far been publicly identified infiltrated the SWP, a Trotskyite party of a few thousand members that advocates the abolition of capitalism through revolutionary means.