The Cinderella actor successfully argued that the publication had been harassing her by sending freelance journalists to linger near her home after she had asked they go away.
She told the regulator that the press attention had caused her to move home.
The Mail published 51 articles online about James over a four month span though IPSO said the articles themselves did not amount to harassment but the constant presence of journalists at her home did.
James also said that the newspaper breached her privacy by snapping photos of her dining in a restaurant.
The Mail argued the level of attention it gave James was protected by the European Convention on Human Rights.
The 51 articles under complaint were published between 12 October 2020 and 2 February 2021. 18 of them were published in a single week — between 12 and 19 October — with seven on the 13th alone.
IPSO said that the articles from that week focussed on James being abroad with another married actor. Articles in The Mail indicate that the actor in question was Dominic West who James starred with in the BBC's adaptation of The Pursuit of Love.
The former Downton Abbey actor told IPSO that the Mail created “a market for photographs of her”, as a result of which “a photographer had pursued her while she was in a removal van, in an attempt to discern the location of her new home".
Before making the formal complaint to IPSO, James contacted the regular three times over "persistent and intrusive approaches from the press”.
The Mail did not accept IPSO's findings. They argued that there was a "public interest" in the photographs and claimed James was breaking Covid-19 restrictions during her visit to the restaurant.
IPSO rejected the claim and said James was attending a business meeting.
IPSO has ordered that a link to the full adjudication be linked on the top half of Mail Online’s homepage “for at least 24 hours, and should then be archived in the usual way”.
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