Mr Justice Nicklin, who oversaw a High Court trial in London in November, ruled in her favour on Thursday.
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Ms Turley said a 2017 article on Mr Walker’s left-wing Skwawkbox blog, which contained a press statement from Unite, libelled her by conveying the meaning that she had acted dishonestly when submitting an application to join the union.
She also said Unite had misused her private information.
Unite bosses and Mr Walker fought the case and said Ms Turley had been dishonest and was not fit to be an MP.
They said the article was true or justified in the public interest.
Mr Justice Nicklin found Unite and Mr Walker liable.
A Unite spokeswoman said Unite bosses were “very disappointed” with the decision. Lawyers said the union and Mr Walker wanted to appeal.
Ms Turley had originally wanted more than £100,000 in damages.
The article related to a Unite membership application Ms Turley made in December 2016.
Mr Justice Nicklin heard how Ms Turley had applied to be a Unite member under a community membership category, which was aimed at people not in paid employment and cost 50p a week.
A barrister representing Unite said Ms Turley had been willing to “conceal, mislead and deceive”.
Anthony Hudson QC said Ms Turley wanted to vote against Unite general secretary Len McCluskey in an election without being noticed and without the union knowing she was an MP.
Ms Turley said the Skwawkbox article made “false and defamatory” allegations about her and impugned her honesty.
“I had not dishonestly joined the community section of Unite and there was no reason to suspect me of being dishonest,” she told the judge. “I believed I was entitled to join it.”
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She added: “I am not dishonest and have not lied or sought to mislead. My reputation for honesty and integrity are of the utmost importance to me. They go to the root of who I am and why I am in public service.”
Mr Hudson said her application flowed from a Birthday Club WhatsApp discussion.
He said the Birthday Club members had come together to oppose Mr Corbyn’s leadership.
Ruth Smeeth, who was then Labour MP for Stoke-on-Trent North, had circulated a link to Birthday Club members about a Unite general secretary election.
Additional reporting by Press Association