Conservative MP Brad Trost is taking his party to court.

Trost filed a request for judicial review on Tuesday, asking the Ontario Superior Court to review whether or not his leadership campaign was wrongly penalized by the Conservative Party of Canada over the leak of a party membership list.

He wants the party to return the $50,000 his campaign was fined after the Conservative leadership organizing committee found his team to blame for an industry association obtaining a party membership list.

In June, the Conservative Party announced that a membership list had been improperly shared after members reported receiving correspondence from the National Firearms Association.

The membership lists contain the names of party members and their contact information, and were provided to the leadership candidates to contact and recruit supporters.

Not long after the leak surfaced, the Conservative Party said that it had identified Trost’s campaign as the culprit of the leak. As a result, the party said it wouldn’t be giving Trost back his $50,000 compliance deposit that was paid when the race got underway.

Trost’s team disputed this, saying they could find no evidence of the leak coming from a campaign member. The details of this back-and-forth were rehashed in Trost’s request for judicial review.

In the court request, Trost alleges the party’s decision to dock him the $50,000 was “procedurally flawed and tainted by a reasonable apprehension of bias.”

Trost said he was aware the party had “salted” the membership lists with a few fake names to track versions of the list given out to the candidates, in case a leak happened. He said he only gave access to the list to a “small number of trusted campaign workers and volunteers.”

In the documents filed Tuesday, the MP for Saskatoon-University says the fine the party imposed is unreasonable. Trost argues that he shouldn’t have been found absolutely liable, considering Conservative Party executives would have also had access to the list in question, an option Trost alleges wasn’t investigated.

In the application for judicial review, Trost names a number of top Conservative Party officials, including leadership election organizing committee chair Dan Nowlan and the other members of the committee.

The unsuccessful Conservative leadership candidate garnered headlines during the campaign for the social conservative support he was able to drum up. It was that pool of supporters that helped propel Conservative Leader Andrew Scheer into his current position. Trost was not given a position in Scheer’s shadow cabinet announced last week.

“Our Leadership rules set out a process for appealing decisions any campaign may not agree with. 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,” Conservative Party spokesperson Cory Hann told CTV News in a statement.