The House of Commons Board of Internal Economy has requested that New Democrat MPs pay back $1.17 million for ineligible mass mailouts, which the board says were partisan in nature but sent out using parliamentary resources.

"Of this amount, about $36,000 is owing to the House and $1.13 million is associated with the use of franking privileges," Conservative MP and chair of the board John Duncan announced Wednesday afternoon.

Duncan said the board cannot compel the MPs to repay the costs associated with their ineligible mailing privileges, but that "it is incumbent on these members to work with Canada Post to repay the $1.13 million."

The powerful but secretive board has been investigating almost two million partisan flyers sent by the NDP MPs to households in 26 different ridings, including four that were in the midst of byelections late last year.

The board is made up of four Conservative MPs, two NDP MPs and one Liberal MP.

'Kangaroo court'

The New Democrats were quick to respond to the board's ruling, with NDP MP Peter Julian immediately holding a news conference with party lawyer Julius Grey.

Julian decried the process by which the board arrived at a decision, calling it "a kangaroo court."

"We believe we have followed the member's bylaws and the Canada Post Act and we will now have to fight this process by a partisan, secretive body that is dominated by Conservatives."

"None of this will hold up in a court of law," Julian said.

Canada Post had little to say about the board's conclusions.

"We will review the decision by the Board of Internal Economy and have no further comment at this time," Canada Post spokesman Jon Hamilton told CBC News in a statement.

"It is obvious that we have a direct assault on the basic principles of the Constitution. In these circumstances, there is no choice but to proceed to judicial review," Grey said.

Tom Mulcair said earlier Wednesday that a guilty verdict and repayment order would not come as a surprise.

NDP Leader Tom Mulcair along with 22 other NDP MPs have been asked to repay $1.17 million for ineligible mass mailouts. (Adrian Wyld/The Canadian Press) "We're taking it for granted, frankly, that they're going to come out against us," he said.

He complained that the board offered the party "no process, no right to be heard, no right to educe evidence, no right to see that the rules are applied equally to everyone."

Duncan has said the Commons could garnishee the budgets of New Democrat MPs if they don't voluntarily repay.

As he has done repeatedly since controversy erupted over NDP mailings and satellite offices several months ago, Mulcair insisted New Democrats have followed all the rules.

The Speaker of the Commons, Andrew Scheer, and House of Commons administration have contradicted NDP claims that they approved the mailings or the use of MPs' office budgets to pay staffers in satellite offices.

The following 23 NDP MPs sent out mass mailings that the board judged improper: