A Labour candidate joined a trade union with the ultimate aim of ousting her own party leader, a court has heard.
Anna Turley claims the Unite union libelled her in an article on an internet blog relating to her application for membership.
But London's High Court heard Ms Turley, who is standing in Redcar, Teesside, wanted to join the union without it being known she was an MP.
Ms Turley has told the court she did not make any "false declarations".
Ms Turley said she had been unaware she broke rules when applying to join the union at a reduced membership rate.
50p a week
Lawyers for the union and blog writer Stephen Walker have branded Ms Turley as "dishonest" and "unfit to be an MP".
The court heard in December 2016, Ms Turley applied to join Unite under a Community membership category, which cost 50p a week and was aimed at people not in paid work.
She said she had done this in error and tried to amend her membership a year later.
Mr Walker, who publishes the Unite-supporting Skwawkbox blog, then wrote an article which Ms Turley said libelled her.
However, lawyers for the union told Mr Justice Nicklin that Ms Turley had been willing to "conceal, mislead and deceive".
The court heard how Unite general secretary Len McCluskey was a major supporter of Labour leader Jeremy Corbyn, and that Ms Turley had links to a WhatsApp group of Labour MPs - known as the Birthday Club - who opposed Mr Corbyn.
Anthony Hudson, for the union, said Ms Turley's membership application was part of an attempt to "oust" Mr McCluskey and that the ultimate aim had been to "oust" Mr Corbyn as Labour leader.
He said: "(Ms Turley) wanted to join Unite without being noticed and without (Unite) knowing that she was an MP."
Mr Hudson said Ms Turley's aim was to "vote against the general secretary with a view to trying to undermine Unite's support for the leader of her political party and the leader of the opposition, with the ultimate aim of trying to remove and replace the leader of her party".
In evidence, Ms Turley said: "I didn't make any false declarations."
She said: "My understanding of the Unite Community was that it was a community-based, grass-roots, campaigning political organisation. I thought I was entitled to join.
"I joined to vote in the election. I have always been very clear about that. I joined it to have a vote and to vote out Len McCluskey.
"I really have been very disappointed for a long time about the influence Len McCluskey has had over the (Labour) party."
The trial continues.