Elections Canada has laid charges against four Conservative Party officials - two of them senators - for allegedly breaking election law during the campaign for the 2006 ballot.
Those charged include Senator Doug Finley, a former party campaign manager, and Senator Irving Gerstein, a major Tory fundraiser.
The charges were filed in an Ontario court this week and are part of a long-running battle between Elections Canada and the Conservative Party regarding more than $1-million in election expenses.
In 2008 the Mounties raided Tory party headquarters in connection with the controversy over the so-called in-and-out financing scheme.
Elections Canada alleges the Tories broke federal law in 2006 election campaign by skirting an $18.3-million spending cap, instead shifting extra advertising expenses to candidates - who are governed by separate expenditure limits.
The federal elections agency has said this was a tactic to claim national campaign expenses as local expenses in 67 ridings and exceed the national campaign-spending limit by $1-million.
The Tories, who say the scheme is legal, sued Elections Canada.
A Conservative Party official Thursday night would only speak on condition he not be identified.
He played down the charges, saying the Tories are unfazed. "We are not surprised. Elections Canada has been pushing for this for two years."
The Conservatives won a legal victory in their fight against Elections Canada but the elections agency is currently appealing it.
"We're disappointed that administrative charges have been laid by Elections Canada after losing in federal court and not waiting for the appeal court decision in this matter," the Tory official said.
"We're confident there won't be convictions. This is an administrative and accounting dispute."
Also charged this week are Michael Donison, the party's former executive director and Susan Kehoe, a senior Tory staffer.
The Conservative Party official played the charges down Thursday night, calling them merely "administrative" in nature.
The charges are not criminal ones, but, according to CTV News, a guilty verdict could result in a $1,000 fine or three months in jail - or both.
In 2010, the federal Conservatives won a court victory over Elections Canada in the case.
Last year, federal Court Judge Luc Martineau rejected Elections Canada's contention that advertising expenses claimed by certain Tory candidates should have instead been reported as part of national campaign spending.