Undercover police officers had long-term sexual relationships with political activists and joined them at family gatherings and on holidays to make their targets “emotionally dependent” on them, according to papers submitted to the high court.
The allegations were revealed at the start of a legal attempt by the Metropolitan police to have the claims heard in secret.
Ten women and one man have launched a legal action claiming they were conned into forming “deeply personal” relationships with the police spies.
The case is the first civil action to be brought before a court since the Guardian revealed police officers frequently slept with political campaigners as part of a spy operation over four decades.
Lawyers for the police are applying to have the cases struck out of the high court and moved to a little-known tribunal that usually deals with complaints about MI5.
The solicitor Harriet Wistrich, who is representing most of the claimants, said: “These women are suing for a gross invasion of privacy, and the Met’s response is to try and hive it off into a secret court.”
Most of the claimants had long-term and serious relationships with police spies, one lasting nearly six years. One was a man who had a close personal friendship with a police spy who ended up having a sexual relationship with his girlfriend.
The submissions also refer to the case of a woman who had a child with an undercover officer who was spying on her and who vanished from her life when the deployment came to an end.
Three of the women referred to in court had intimate relationships with Mark Kennedy, who spent seven years living as an environmental campaigner. Details of Kennedy’s deployment were made public last year after activists worked out he was a police mole.
Two other women in the case had sexual relationships with a colleague of Kennedy’s who served undercover alongside him. The police spy claimed to be a truck driver called Mark Jacobs when he infiltrated a small anarchist group in Cardiff until 2009.
As Jacobs, he had taken part in “deeply personal aspects of their lives”, even attending the funeral of one woman’s father after he died of cancer, barristers told the court in their written legal submissions.
“In doing so, he had exploited the vulnerabilities of the claimants and sought to encourage them to rely on him emotionally,” the documents added.
“Jacobs” had instigated a sexual relationship with one of the women, the court was told, while she was going out with another male activist, who is part of the legal action.
“During the course of those relationships, Jacobs purported to be a confidant, empathiser and source of close support to each of the claimants,” the barristers said.
Lawyers for the 10 women involved in the joint legal action against the Met, which had overall responsibility for the deployment of the spies, claim the deception caused their clients “serious emotional and psychiatric harm”.
They told Mr Justice Tugendhat the undercover officers had used the long-term relationships to gather intelligence on the women or for their own “personal gratification”, while pretending to support them emotionally.
They said the “grave allegations” of police misconduct raised serious questions about the “extent to which covert police powers have been and may in future be used to invade the personal, psychological and bodily integrity” of members of the public.
There is confusion over the rules governing the conduct of police spies. Senior officers have claimed it is “never acceptable” and “grossly unprofessional” for undercover officers to sleep with their targets; however, a government minister recently told parliament the tactic was permitted.
The evidence uncovered by the Guardian suggests the practice is routine. Eight of the nine undercover officers identified over the past 21 months are believed to have had intimate sexual relationships with protesters they were spying on.
Documents submitted to the court allege that Kennedy attended intimate family gatherings with all three women and joined them on holidays.
“He discouraged [them] from terminating the intimate sexual relationships,” their barristers said.
Kennedy, who was married with two children, had one relationship with an activist for two years. Another activist, who became his long-term girlfriend, was in a relationship with the police spy for six years.
Phillippa Kaufmann and Heather Williams, QCs for the women, who want to remain anonymous, said none of them would have had agreed to have had sex or entered “the most intimate of relationships” if they had known the men were police officers.
Monica Carss-Frisk QC, for the police, said their argument was not about denying the women remedy, but determining the correct forum for determining their claims.
The police argue the case should be heard in the investigatory powers tribunal, as it was set up specifically to consider allegations of unjustifiable surveillance by the state.
They also argue they may be unable defend the case because they have a long-established policy of neither confirming nor denying the identity of undercover police officers.