Longtime Conservative MP Brad Trost has lost his bid to sue the Conservative Party over what he claimed was a "deliberate smear" during last year's leadership race.

Trost took legal action after his campaign was slapped with a $50,000 fine for leaking the Conservative membership list to the National Firearms Association, a gun owners rights group.

A ruling released Monday by the divisional court of the Ontario Superior Court of Justice found there was no jurisdiction for his request for a judicial review because it was a matter involving a private organization.

"The Conservative Party of Canada is a voluntary association. While it plays a very important role in the Canadian political system, it is nevertheless a private actor, and its decisions are not subject to judicial review," the decision reads.

Trost, who finished fourth in the leadership race, said his fight was not with current party leader Andrew Scheer, but with "factions inside the party" he said were working against him.

The Conservative Party uses a practice known as "salting" to trace leaks of its membership list. Each leadership campaign received a slightly different copy of the list to allow officials to trace back unauthorized releases.

Trost insisted that neither he nor anyone else from his campaign leaked the list, and suggested it could have been leaked by someone at party headquarters who had access to all versions of the list.

On Tuesday, Trost's former leadership campaign manager Joseph Ben-Ami issued a statement saying party officials failed to follow their own "basic standards of procedural fairness in dealing with this issue."

"We are disappointed that the judges in the latest hearing have seen fit to repudiate emerging case law that increases protections for the rights of members of political parties," Ben-Ami said in the statement. "We are currently reviewing all of our options and will have more to say soon."

'Final and binding'

When he entered the leadership race, Trost signed forms with the Leadership Election Organizing Committee [LEOC] acknowledging the committee had the authority to disallow his candidacy on any grounds, and that the decision would be final and binding.

It also acknowledged than any ability to appeal a decision by the Chief Returning Officer would rest with the LEOC's dispute resolution and appeals committee — and that committee's decision would be "final and binding and not further appealed or challenged."

Conservative Party spokesman Cory Hann welcomed the court ruling.

"We're pleased the court agreed that this is an internal party matter, and a matter that shouldn't cost the Conservative Party and its members and donors unnecessary legal costs," he said in an email.

In June 2017, the LEOC decided that Trost had contravened the rules governing the leadership contest because his campaign was responsible for a leak of confidential information.

He was fined $50,000, the amount he had been required to pay as a compliance deposit.

Yesterday's ruling awards $22,000 in legal costs to the Conservative Party.

In March, Trost lost his party's nomination for next year's election.