OTTAWA - Cries of a coverup competed with claims of pre-election, hyper-partisan excess Wednesday after Liberal MPs blocked an opposition attempt to hold hearings on ethics commissioner Mario Dion's scathing report into Prime Minister Justin Trudeau's handling of the SNC-Lavalin affair.

Only one of six Liberal MPs on the 10-member House of Commons ethics committee supported a Conservative motion to call Dion, and possibly others, to testify about the report.

The lone Liberal outlier, Toronto MP Nathaniel Erskine-Smith, supported the motion only because he said he wanted Dion to explain what he considered the commissioner's “legally flawed” conclusion that Trudeau broke the Conflict of Interest Act.

All six Liberals voted against a subsequent NDP motion to call Trudeau, Finance Minister Bill Morneau and his former chief of staff, Ben Chin, to testify about their roles in the affair.

They were joined by New Democrat Charlie Angus in defeating another Conservative motion which would have called on CBC journalist Aaron Wherry to table all his recordings and notes from interviews with Trudeau in his newly released book on the prime minister's first term in office, “Promise and Peril.”

Speaking for his fellow Liberals, Quebec MP Steven MacKinnon dismissed the motions as blatantly partisan attempts to re-ignite public outrage over the SNC-Lavalin controversy on the eve an election call.

“This has been an exhaustively analyzed situation,” MacKinnon said following a three-hour emergency meeting of the ethics committee.

“We've had 13 hours of testimony, we've had 10 witnesses, we've had five weeks of hearings (by the justice committee), a 63-page report (from Dion).”

He called the attempt to force further hearings “a partisan game,” in which opposition parties deployed “their most partisan, paint-peeling members” to Wednesday's committee meeting - referring to deputy Conservative leader Lisa Raitt and Ottawa MP Pierre Poilievre, both of whom spoke at length during the meeting although they couldn't vote on the motions because they're not committee members.

“So I think we all know that on the eve of an election, this kind of partisan gamesmanship by the opposition is what it exactly appears to be,” said MacKinnon.

In turn, Conservative MP Peter Kent accused Liberal committee members of abdicating their responsibility to “shine a little light on the SNC corruption scandal.”

“Instead, they joined the prime minister in attempting this coverup. They are complicit in his attempt at obstruction of justice.”

Kent also referred to MacKinnon, who was filling in on the committee for another Liberal MP, as a “hit man” deployed by the Prime Minister's Office to gag his fellow Liberals.

Dion was “standing by,” prepared to immediately testify via video conference had the committee voted to hear from him. As it turned out, he needn't have bothered.

In a report released last week, Dion concluded that Trudeau broke the Conflict of Interest Act by improperly pressuring former attorney general Jody Wilson-Raybould to halt a criminal prosecution of SNC-Lavalin on corruption charges related to contracts in Libya.

Dion also disclosed in his report that he couldn't get all the information he required, as potential witnesses claimed cabinet confidence stopped from them from sharing everything they knew.

Trudeau has acknowledged that he wanted Wilson-Raybould to reconsider her refusal to overturn a decision by the director of public prosecutions, who decided last fall not to invite the Montreal-based engineering and construction giant to negotiate a remediation agreement. Such an agreement would have allowed the company to avoid the risk of a criminal conviction, which would result in it being barred from federal contracts for 10 years.

While he has taken full responsibility for the mistakes that were made, Trudeau has refused to apologize. He has insisted that he was only standing up for the interests of SNC-Lavalin's 9,000 employees, pensioners and suppliers, who stood to be negatively affected by the potentially crippling cost of a conviction.