Conservative senators filed into a closed door caucus meeting Tuesday as debate over whether to suspend three embattled senators drags on for the sixth day.

Prime Minister Stephen Harper’s former chief of staff Nigel Wright did not authorize a controversial payment from Conservative Party funds to pay off Senator Mike Duffy’s legal bills but the Conservative Party isn’t saying who signed off on the $13,560 deal.

While Duffy told the Senate that Wright arranged the payment, Jason MacDonald, director of communications to Harper, says Wright would not have had the power to actually authorize it. However, Cory Hann, spokesman for the party has yet to answer questions from iPolitics about who did okay using party funds to pay Duffy’s legal bills.

“At the time these legal expenses were incurred and paid, Mike Duffy was a member of the Conservative caucus,” Hann said in an email. “Like all political parties, the Conservative Party sometimes assists members of caucus with legal expenses.”

The Conservative Party issued a directive to members Tuesday, urging them not to speak to reporters about Duffy’s revelations and to refer all calls to Hann.

Meanwhile, the Conservatives moved to use their majority in the Senate to restrict debate on three controversial motions to suspend Duffy as well as Senators Pamela Wallin and Patrick Brazeau.

Senator Claude Carignan, the government’s leader in the Senate, said he is concerned the Liberals will use tactics to delay the vote on the motions and stop the Senate from moving on to other issues.

If the Liberals try to delay debate, a vote on the fate of the three embattled senators may not come before Conservatives meet in Calgary later this week for their policy convention.

Bombshell allegations by Duffy fuelled question period in the House Tuesday, particularly his revelation that the money to pay his legal bills came out of Conservative party coffers and the cheque was written by the Conservative Party’s lawyer Arthur Hamilton.

The legal bills were the result of negotiations between Duffy and Wright to have Duffy tell the public he had repaid $90,000 in housing expenses he had claimed. It was later revealed that Wright provided the $90,000 to pay back the Senate.

“Yesterday, Senator Duffy said that there were at least two cheques involved in this deal with the prime minister’s office,” NDP Leader Thomas Mulcair stated during a fiery question period. “How many cheques were there?”

Harper, however, defended the decision to pay Duffy’s legal tab.

“The party regularly reimburses members of its caucus for valid legal expenses as do other parties.”

“What was shocking and unacceptable in this case is that Mr. Duffy had collected inappropriate money from the taxpayers of Canada,” Harper continued. “He had been told by everybody he should pay it back. He had said he would pay it back. He had said he did pay it back, and that all turned out to be untrue, which is why Mr. Duffy should be removed from the Senate.”

Mulcair then shot back demanding to know how many people knew about the second cheque and questioning Harper on his assertion in May that there was “no legal agreement in the Duffy affair.”

“How many lawyers does it take to negotiate no legal agreement,” Mulcair said, mocking Harper.

The senate spending scandal dominated question period Tuesday, with Mulcair attacking Harper relentlessly for much of the 45-minute session. While Harper didn’t appear to slip up, he became more short-tempered as the barrage continued.

Since Mulcair kept coming back with question after question and by tradition the prime minister answers questions posed by the opposition leader but not backbench MPs, it meant that Harper ended up on his feet for much of question period.

The Liberals took a somewhat different tack. Liberal Leader Justin Trudeau led off the Liberal questioning, calling on Harper to testify under oath about the scandal. But follow-up questions such as Marc Garneau’s about whether the government still had confidence in Chris Woodcock, who drafted the talking points for Duffy. or whether the justice minister had referred lawyer Benjamin Perrin’s action to the law society, were deflected by Harper’s parliamentary secretary, Paul Calandra.

After Monday’s bombshell revelations by Duffy, Tuesday’s Senate debate descended into procedural wrangling. However, Liberal House Leader James Cowan denied his MPs were trying to drag out the debate.

“The question is why are they bringing in these motions,” Cowan told reporters. “Why are they bringing in these motions right now? It’s not our choice, it’s theirs. Not only do they bring them in, that’s their choice not ours, then they want to close the debate because the PM’s story is starting to unravel.”