Protesters blockaded New Scotland Yard today, calling for a judge-led inquiry into the use of undercover policing.
Dozens lined the entrance to the Metropolitan Police headquarters in Westminster to demonstrate against the tactic of infiltrating protest movements to gather intelligence.
The picket consisted mainly of women protesters, bearing posters of three officers who have been exposed as uncover police, as well as silhouettes representing other undercover officers who remain unidentified.
The group called on police to name officers who have been covertly involved in protest movements to reveal whether any others had formed relationships with women protesters.
The calls came after ex-Metropolitan police officer Mark Kennedy was exposed as an undercover officer who spent a reported seven years undercover posing as an environmental activist known as Mark "Flash" Stone.
Sophie Stephens, spokesman for the blockade, said: "It's time for the abuse of women by undercover police officers to stop. If a person is pretending to be somebody else, if they are spying on you,
then you absolutely cannot give your informed consent."
"Women are not able to make an informed decision about who they are having a relationship with if they are being duped by police officers."
"We also want a judge-led inquiry. We don't trust the police to police themselves. They have showed time after time they believe they are above the law," she added.
Officers on motorcycles gathered to police the protest, which included environmental campaigners and others involved in social justice movements.
One of the protesters, who gave her name only as Sarah, said she knew women who had had relationships with undercover police officers.
She said: "People we know and work with have had relationships with undercover policemen who they didn't know were policemen and there is no way they could have given their consent.
"I know they are feeling angry and betrayed. It's overwhelming - I had no idea this kind of thing could happen in this country.
"What we want to know is who the undercover policemen are."
Sam Lyas (23) also joined in the blockade and said: "This is just an abhorrent thing to happen. The police specifically condone undercover policemen having sex to glean information. It's sanctioned by the state."
"I'm here to show my support. Hopefully, there's going to be an independent inquiry into how undercover policing is used in the UK."
PA