Opposition MPs say the Conservative government's silence over a controversial boast from Peter Penashue speaks volumes about the former minister's credibility.

New Democrat Jack Harris was one of several MPs to focus Monday on Penashue's claim last week that he deliberately held up an unspecified project in Newfoundland in order to help his own constituents in Labrador.

Penashue made the claim before cheering supporters in Happy Valley-Goose Bay where he is the Tory candidate in May's Labrador byelection.

To date, no one has identified the project that Penashue claims he held up. Newfoundland and Labrador Premier Kathy Dunderdale has said she has not been able to confirm what it was.

"The fact is that Mr. Penashue has failed to come clean for his last campaign, and Conservatives just do not care, just as they do not care when Mr. Penashue pits region against region," said Harris, who represents St. John's East.

"Will the Conservatives now admit it was wrong for Mr. Penashue to brag about withholding project funding for Newfoundland to favour his own riding, or will they continue to defend this unacceptable behaviour by their former and now disgraced minister?

Pierre Poilievre, a parliamentary secretary who answered many of the questions about Penashue before he resigned his seat last month amid an Elections Canada investigation into his 2011 campaign spending, did not address the questions directly, but instead lauded Penashue's 22 months in office.

"Mr. Penashue is delivering for Labrador. He has delivered jobs through the Muskrat Falls project. He has delivered for hunters who have demanded for years to have the long gun registry scrapped, something that the NDP, including its rural members, failed to join us in doing," Poilievre said.

Poilievre also noted that Penashue has "worked to expand funding for the Trans-Labrador Highway," the project that Penashue said won support at the expense of one on Newfoundland.

Liberal MP Scott Andrews, who represents the eastern Newfoundland riding of Avalon, asked if Prime Minister Stephen Harper knew what Penashue meant.

"To the prime minister: can he help poor old Peter out and inform this House exactly what projects were held up, or was Peter just making it up?"

Poilievre also answered that question.