Guergis was ejected from cabinet and from caucus in 2010 amid allegations she was caught up in criminal activity with her businessman husband Rahim Jaffer. The RCMP later said they could find no reason to charge them.
Now she's trying to bring a $1.3-million defamation and conspiracy case to court against Harper and several Conservative figures — and, in the process, floating the purely hypothetical theory that the prime minister himself was the source of the defamatory claims.
One of the central themes of Guergis's lawsuit is that she was defamed when Harper told reporters that he had received serious allegations about her, and then again when a letter was sent to the RCMP citing allegations received by the prime minister's office.
Guergis' statement of claim entertains three possibilities. One, that private detective Derrick Snowdy went to the party's lawyer with allegations in April 2010, thus defaming her.
Two, that Snowdy did no such thing, but that the party lawyer made the allegations up when he communicated them to the prime minister's office shortly afterward.
Or three, that neither Snowdy nor Hamilton communicated allegations, but that Harper made them up when he made his public statement and wrote to the RCMP.
"These are very serious allegations being made against Mr. Harper and the prime minister's office," said Ontario Superior Court Justice Charles Hackland.
"It's unfortunate that one is left to speculate about what is claimed here."
Guergis's lawyer Stephen Victor said his client couldn't possibly know exactly what happened because everything occurred behind closed doors, which is why it's important that the case go to trial.
There's nothing legally wrong with having inconsistencies in a statement of claim, Victor said.
"I don't have to go there — I don't know. That's only within the knowledge of the defendants as to what occurred," he said.
"That's too great an onus to put on Ms. Guergis as the person defamed."
The defendants are trying to get the case dismissed this week, principally on the grounds that the actions of Harper and his team are constitutionally protected.
Robert Staley, Harper's lawyer, didn't specifically respond Thursday to suggestions that his client could be the source of the allegations. But on Wednesday, he delivered a withering assessment of Guergis's claims, calling them "gibberish" and "a fiction" with no basis in fact.
"This is throwing things against the wall to see what sticks,'' he told Hackland. "This is just plain bad.''
Victor argues that the case has nothing to do with Harper's protected right to remove her from cabinet, but rather on what he did beforehand — namely defaming her by publicly alluding to allegations of criminal activity.
Guergis's team also rejects the notion that Harper and his senior officials were simply exercising their public duties when they communicated to the RCMP and to the public. Part of her claim against Harper and his staff is "misfeasance in public office."
If Harper or his staff made up the allegations, then they were not engaging in their public duties, Victor argued. And if they did genuinely receive allegations, there was never a need to unilaterally broadcast them and pass them to the RCMP as they did.
Earlier in the day, Conservative party lawyer Paul D'Angelo presented arguments as to why the party could not be sued for damages. Guergis is pursuing the party partly because it did not support her continued nomination as the candidate in the riding of Simcoe-Grey.
He said political parties can be challenged on Canada Elections Act issues or in an application for judicial review, but that an unincorporated association can't be sued for inflicting harm on an individual such as in this case.
D'Angelo said Guergis did not actually use the appeals processes available to her through the party's constitution and nomination rules.
Guergis ran as an independent in the 2011 election in Simcoe-Grey and lost. Shortly afterward, the conflict of interest and ethics commissioner found she had broken the rules when she wrote a letter on government letterhead to a local politician about a businessman in her riding. That businessman had been in talks with Jaffer about possible transactions.
The defendants in the defamation case include Harper, his principal secretary Ray Novak, his former chief of staff Guy Giorno, Hamilton, Snowdy, Labour Minister Lisa Raitt and her former assistant Axelle Pellerin, MP Shelly Glover and the Conservative Party of Canada.
Her lawsuit includes a range of claims, including defamation, conspiracy, misfeasance in public office, intentional infliction of mental suffering and negligence.