In a statement, Conservative whip John Duncan said House of Commons officials will begin rejecting claims from NDP MPs who are accused of using public money to pay for so-called satellite offices across the country.
Any expenses incurred starting on Canada Day are set to be rejected starting Thursday when Commons officials return to work, unless 68 current and former MPs repay the money the multi-party board of internal economy says they owe the public purse.
"For over a year, the NDP has done everything they can to deny, delay, and obstruct an investigation into their use of parliamentary resources for partisan satellite offices," Duncan said in the statement.
"Now...individual members will be having their claims for expenses denied by the House of Commons."
Duncan's office has yet to respond to additional questions posed by The Canadian Press.
The NDP has strenuously denied that its MPs did anything wrong, saying they followed House of Commons spending rules when the offices were opened.
The party is challenging the board's finding in Federal Court, calling the decision a politically motivated attack by the Conservatives and Liberals made behind closed doors in a "kangaroo court."
A spokesman for NDP Leader Tom Mulcair questioned the timing of the announcement, given the court is still set to hear arguments in the case.
"The fact that mere weeks before the election, the Conservatives would not wait for the court and instead try to handicap the official Opposition speaks volumes about the political motivations behind all of this," said Karl Belanger, Mulcair's principal secretary.
The MPs are accused of using public money from their office budgets to pool funds in order to create the outreach offices, which the party set up after the 2011 election when an unprecedented number of NDP MPs were elected across the country — particularly in Quebec.
The board has previously said that Commons officials believed all the workers in the outreach offices would work in Ottawa, but later found out that they were in offices in Quebec. The board decided the offices were a violation of Commons spending rules because the employees hired in each office were neither working in a constituency office, nor a parliamentary office.
The NDP was ordered to repay about $2.75 million or face sanctions, which would include having their hospitality, per diem and travel expenses rejected.
MP spending figures posted this month show 67 of the 68 MPs caught in the satellite office issue spent on average about $13,600 per month on travel for themselves, $6,250 on per diems, and about $5,200 on hospitality expenses.
Olivia Chow is excluded because she resigned in early March 2014 to run for mayor of Toronto, meaning she didn't file an expense claim as an MP during the 2014-15 fiscal year, which started in April.
There is also a second possible measure that could be used against first-term MPs who decide to retire or lose in the fall election: having their so-called separation pay and pension contributions clawed back by the Commons.
Separation pay, or severance, is worth about half of an MP's annual salary, or about $81,850 for any MP who qualifies for the payment this year. If the MP hasn't been in the Commons for the minimum six years necessary to qualify for a parliamentary pension, they can walk away with a cheque for their contributions that could amount to $100,000 over a four-year period.
The NDP had also been previously chastised by the board of internal economy for sending $1.17 million worth of political flyers that violated Commons rules.
MPs are allowed to send flyers free of charge to constituents so long as they are for parliamentary business, and not to help a party campaign.
Quietly, the board has also been told that 12 Conservative MPs violated the same rules. The cost to the Commons was $6,314.18, according to the report provided to MPs on the board, and a further $112,837 would be owed to Canada Post.
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