After days of being on the defensive over an alleged coverup to repay Mike Duffy's ineligible expenses, Prime Minister Stephen Harper found something to pin on the leader of the Opposition during question period on Wednesday.

Mulcair asked Harper, for a second day in a row, about the second cheque that Senator Duffy said was given to him by Nigel Wright, Harper's former chief of staff, to help him pay his legal fees.

Duffy told the Senate on Monday that Wright arranged to have $13,560 in legal fees paid by the Conservative Party — in addition to the $90,000 cheque Harper's then chief of staff gave Duffy to repay his ineligible expenses.

Harper repeated what he had told the Commons on Monday, that it is common practice for the party to assist members in good standing "from time to time."

The prime minister then took direct aim at Mulcair and asked the NDP leader about "his party" repaying his legal expenses to the tune of $100,000 in a libel case.

"How many members of the NDP are aware that this party leader not only claims expenses for court cases he loses, but also expects his political party to actually pay for him the damages imposed by a court of law?" Harper asked.

Mulcair never gave Harper the satisfaction of a reply despite numerous attempts by the prime minister to draw an answer from him.

In 2005, a court ordered Mulcair, who was an elected official sitting in the national assembly for the Quebec Liberal Party at the time, to pay $95,000 in damages to Yves Duhaime​.

Duhaime, a former Bloc Québécois MP, was working as a lobbyist when he sued Mulcair for defamation in 2002.

The Liberal Party of Quebec paid for the damages as well as Mulcair's legal costs.

Conservative Party lawyer Arthur Hamilton, who wrote the $13,560 cheque to cover Duffy's legal fees, also assisted MP Dean Del Mastro while he was in caucus.​

Conservative MP Peter Goldring, however, told CBC News on Wednesday he paid his own "very expensive" legal bills while facing a criminal charge.

Senate amendment under consideration

Mulcair, during a scrum with reporters after question period, dismissed Harper's attack as "something that happened almost 15 years ago with another party, in another parliament."

"It shows the desperation of the Conservatives now. They're on the eve of their big weekend in Calgary, they are looking for anything," the NDP leader said.

Conservatives had hoped the Senate would have voted on the motion to suspend senators Patrick Brazeau, Mike Duffy and Pamela Wallin without pay before the start of the party's annual convention in Calgary Thursday.

However, the Senate is still in the process of considering an amendment that would see the senators keep their medical benefits if they are suspended without pay.

Mulcair told CBC News Network's Power & Politics on Wednesday that he would prefer to see the Senate abolished altogether, but suspending the three embattled senators that Harper appointed without pay is "a good start."

Conservatives who emerged from caucus on Wednesday said it was the Liberals who were stalling the motion to suspend the three senators without pay, but Liberal deputy leader Ralph Goodale said it was the fault of the Conservatives.

"That is 100 per cent the responsibility of the Conservative leader in the Senate and the people in the Prime Minister's Office that are pulling their strings," Goodale said.​

Earlier in the day, Goodale told reporters his party wanted to know, if the legal fees were paid out to Duffy under false pretense would the Conservatives try to recoup the $13,560?

"Are they going to launch proceedings to recover the legal costs from the law firm working for Mr. Duffy?" asked Goodale.

During question period, Harper only answered questions that came directly from Mulcair. He had his parliamentary secretary Paul Calandra answer questions from opposition MPs, including Goodale, who took the lead for the Liberals.

Liberal Leader Justin Trudeau was not in question period on Wednesday, but in Alberta, where he gave a speech to the Calgary Petroleum Club earlier in the day.