The allegations — that Guergis was removed based on unproven allegations, damaging her reputation and political career — are contained in a statement of claim filed with the Ontario Superior Court.
"The conspiracy engaged in by the defendants was effected to serve the defendants' political, personal and/or financial goals and not for any legitimate or lawful purpose," reads the statement of claim, which was obtained by the CBC and posted Thursday on its website.
Harper fired Guergis from cabinet and kicked her out of the Conservative caucus in April 2010. He cited information he had received involving allegations of criminal conduct and referred the matter to the RCMP. Harper did not provide any details of the allegations to Guergis, according to the documents.
"Harper's advice to the plaintiff that he had become aware of allegations that the plaintiff had been involved in criminal conduct constituted flagrant and outrageous conduct," the documents allege.
"The provision of that advice resulted in injury to the plaintiff's reputation, political career, health and well-being."
The allegations were part of information that private investigator Derek Snowdy provided to Arthur Hamilton, a Conservative Party lawyer, and passed on to the prime minister's office, the statement alleges. Both men are also named in the lawsuit along with the party and Hamilton's Toronto law firm.
The police investigation cleared Guergis of any wrongdoing and no charges were ever laid.
"No evidence has ever existed to corroborate the allegations," the statement says.
Guergis was never admitted back into the Conservative fold. She sat as an Independent MP until the May election, when she lost her Ontario riding of Simcoe Grey to Conservative Kellie Leitch.
The claims contained in the documents have not been proven in court and no statement of defence has been filed, but the prime minister's office calls the allegations groundless.
"This latest action is ridiculous. The voters have made their minds up on Helena Guergis," PMO spokesman Carl Vallee said in an email to The Canadian Press.
Also named in the legal action are Labour Minister Lisa Raitt, MP Manitoba MP Shelley Glover, Axelle Pellerin, who was an aide to Raitt, and two men who were senior aides to Harper at the time, Guy Giorno and Ray Novak.
The suit also alleges that in the months prior to Guergis being kicked out of the party, Harper, Raitt, Glover and their aides started to exclude her from cabinet and caucus activities.
"This conduct was solely the result of negative media coverage involving the plaintiff's spouse and constituted a deliberate and calculated attempt to marginalize the plaintiff," the documents say.
Guergis's husband, former Alberta Conservative MP Rahim Jaffer, came under scrutiny for his activities as a lobbyist after he lost his Edmonton seat in 2008. He also made headlines when an associate had bragged to friends that Jaffer could open doors in Ottawa to potential clients.
Filings to a House of Commons committee revealed Jaffer had been using one of his wife's parliamentary email addresses, a room in her office, and had even handed out an old MP's business card to some prospective clients.
Jaffer insisted he had only ever approached government officials for information about different funding envelopes.