AN ENVIRONMENTAL activist deceived into a two-year relationship with an undercover officer was awarded significant compensation today after winning a landmark case against the Metropolitan Police.

Kate Wilson began a relationship with Mark Stone, whose real name is Mark Kennedy, in 2003 before they split up in 2005.

In 2010, she discovered that he was a married police officer who had been sent to spy on activists as part of the police force’s national public order intelligence unit (NPOIU).

Mr Kennedy had sexual relationships with as many as 10 other women during his deployment, including one with a woman known only as “Lisa” which lasted for six years before she discovered a passport in his real name.

He was one of half a dozen undercover officers from the NPIOU or its “sister unit,” the special demonstration squad, who Ms Wilson met between 1998 and 2010.

The Investigatory Powers Tribunal has ordered the Met and the National Police Chiefs Council (NPCC) to pay a total of £229,471.96 to Ms Wilson “by way of just satisfaction for the breaches” under the European Convention on Human Rights.

The judgment found that the deployment of officers into Ms Wilson’s life and political movements was “not necessary in a democratic society” and was “not in accordance with the law.”

It also found that the Met and NPCC’s failure to guard against the risk of undercover police entering sexual relationships with women amounted to unlawful discrimination against women.

Ms Wilson said that the findings “amounts to a long overdue recognition that spying on protest movement is political policing and has no place in a democratic society.

“It is important because it goes beyond the scandal of undercover officers deceiving women into intimate relationships,” she said.

“Violating our political rights was the entire reason for these deployments and thousands of people will have had their political rights violated in this way.”

Jane, another woman who was spied on by Mr Kennedy, called for a public inquiry and said: “The police spent years manipulating and undermining movements working to make our society a fairer and more just place.

“Where would we be today in addressing climate change, and social injustices without this unlawful interference?”

The NPCC said there had been “significant” changes to undercover policing since the Kennedy affair came to light.