Brad Trost hoped to become party leader, but instead the man who marketed himself to party faithful as "100 per cent Conservative" is now taking the Conservative Party of Canada to court.

Trost's former campaign manager told CBC News that Trost doesn't want to jeopardize party unity, but he feels compelled to fight back against a $50,000 fine for actions the Trost campaign insists it had nothing to do with.

"Nobody on our side wants to give the party a black eye by any stretch of the imagination. But it's not us. We're reacting to what the party has done or is refusing to do to ensure that ultimately justice is done," said Joseph Ben-Ami.

In June, the Conservative Party announced someone had leaked the party's membership list to the National Firearms Association. CBC News first reported that Trost's campaign had been identified as the source of the leak, something the campaign vigorously denied.

On Tuesday, The Canadian Press reported that the Saskatchewan MP had filed a court application over the fine. The court documents, obtained by CBC News, claim the process that found Trost's campaign at fault was "flawed' and "unreasonable," even calling it "a sham designed to justify a decision that had already been made" by party officials.

Trost is seeking to have the $50,000 fine refunded to his campaign, along with court costs and any further "relief" the court deems reasonable. Alternately, Trost is asking the court to have an "impartial decision maker" conduct a fair review.

"Our position has been [that] we feel that there wasn't a proper investigation done," said Ben-Ami.

"The party announced it knew who was guilty and was going to be taking action against them before we were even notified of anything. Was there a sham investigation? Show us the evidence, show us the results of the investigation."

A spokesperson for the Conservative Party didn't comment on the leak itself or any of the allegations made by the Trost campaign. However, Cory Hann suggested the Trost campaign did not need to bring the matter before the courts.

"Our Leadership rules set out a process for appealing decisions any campaign may not agree with," Hann said in an email. "As we have done throughout this, we'll continue to invite the Trost campaign to utilize that appeals process. Our appeals committee remains ready to hear any appeal if or when that process gets used."

'Salted' list in question

In order to keep track of its membership list, it has been widely reported that the Conservatives handed out so-called "salted" copies of the list.

That means each campaign's list would include a few fictitious names on it. The names would vary from one campaign to the next.

It seems that method pointed the party directly to the Trost campaign.

However, in his court application Trost argues that his campaign was never given any evidence of its alleged wrongdoing. The document says a "small number of trusted campaign workers" had access to the list and after an internal investigation, the campaign was confident none of its own people leaked the list.

It also suggests that someone within the Conservative party itself could have leaked the list and that the people in charge of reviewing the leak were "under political pressure to determine that the Trost campaign was responsible for the leak, regardless of what the evidence showed. and therefore would not decide the matter impartially."

Trost facing campaign debt

The party took the money from Trost's campaign by refusing to return the $50,000 compliance deposit that all campaigns were required to hand over during the leadership race.

Ben-Ami said the campaign would have broken even, if that deposit had been returned. Instead they now have to keep fundraising and remain tens of thousands of dollars in debt.

The money to pay for the court application against the party was raised privately and isn't related to campaign funds, Ben-Ami said.

News of the court application comes days after Trost was left out of Andrew Scheer's shadow cabinet. The court documents were also filed the same week that the Conservative caucus prepares to meet in Winnipeg, ensuring that both Trost and Scheer will be peppered with questions about the dispute.

No sour grapes, says campaign

Ben-Ami said the timing is purely coincidental. He also said this is not about the party leader but rather about the party itself and some of its political operatives.

"Brad is very supportive of Andrew Scheer."

Ben-Ami suggests in the long run, if justice is served, this may actually be good for the Conservative party.

"Irrespective of what you think about politics and issues and anything, that's just not the Canadian way. Our party is supposed to be a party of law and order and we take that seriously,"