The Conservatives seemed to want to make a show of what they were about to do.

"Mr. Speaker, in 1990, a minister had to resign for making a telephone call to a judge," Blaine Calkins explained solemnly, a third of the way through question period Tuesday afternoon. "In 1996, a minister had to resign because he wrote a letter to the Immigration and Refugee Board. In 2013, a minister resigned for writing a letter to the federal tax court."

Here were references to the unfortunate cases of John Duncan, David Collenette and Jean Charest, each of whom were found to have crossed the line that is supposed to separate the ministerial from the judicial.

"All of these ministers resigned because of inappropriate contact with judges and tribunals," the Conservative MP concluded. "Is the prime minister going to set the same standard for his government?"

The House was struck silent with anticipation. Surely something exciting (or unfortunate, depending on your perspective) was about to happen. Perhaps the Conservatives had uncovered the first serious scandal of the new Trudeau era. Perhaps someone's time in cabinet was about to be suddenly over.

Dominic LeBlanc, the government's House leader, duly stood and enthused about his side's commitment to transparency and accountability. Attention immediately returned to the Conservative side for the big reveal.

"The reason I asked the previous question is the government House leader wrote, on behalf of the prime minister, to a citizenship judge," Calkins now explained. "He has been busy. The government House leader also wrote to five members of the Immigration and Refugee Board, the same board that former Liberal David Collenette wrote to and had to resign over."

There was some excitement on the Conservative benches.

"How," Calkins asked, "is the prime minister going to hold his House leader responsible for this clear violation of ethical guidelines?"

This seemed less than ideal for the government side.

'Talking about ethical guidelines'

LeBlanc stood to respond and explain. "Mr. Speaker, I was happy to write, on behalf of the government," he said, "to people whose appointments were made by that member's government to take effect after the election, with no ability to be scrutinized by Parliament."

The Liberals around him applauded this context — the House leader referring to his own widely reported request that some of the Conservative government's last-minute appointees voluntarily resign.

Power Panel: Tories accuse government of 'political interference'8:47

"The member well knows there is a difference between writing to a government official about the nature of an appointment and writing to a government official about a specific case before him or her," LeBlanc continued. "The member should know that very well. To confuse the two does no disservice (sic) to Canadians."

Despite the apparent verbal stumble of the House leader, the prime minister, seated beside LeBlanc, seemed satisfied with this explanation and the Liberals stood to concur. The Conservatives, though, pressed on.

"Mr. Speaker," tried Karen Vecchio, a Conservative rookie, "political interference is political interference."

LeBlanc, a willing and experienced combatant, was unmoved.

"Mr. Speaker, talking about ethical guidelines," he said, his fellow Liberals chuckling, "when we are talking about a previous government's decision, at five minutes to midnight, to appoint a series of individuals to jobs to take effect after it lost the election, with no ability for this House to scrutinize those appointments, from our perspective, that was the abuse of process."

Vecchio posited once more that "political interference is political interference" before LeBlanc clarified his distinction.

"We did not talk to people about specific cases or their work, with respect to any independent tribunal," he said. "The members knows that well. She is confusing the issues."

As it turns out, no Conservative MP has yet bothered to bring this concern to the ethics commissioner. And the office of the commissioner has since told CBC News that the commissioner "is of the view that the letters did not seek to influence a quasi-judicial decision." 

But the Conservatives would make at least a rhetorical stand of it this afternoon.

"Mr. Speaker, the government House leader cannot answer a question on ethics because he does not know what they are," Alex Nuttall next condemned from the back row of the opposition side. Nuttall was particularly concerned with the prime minister taking responsibility. "Will the prime minister stand and tell this House how he will fix the obvious ethical breach?" he asked.

Once more to LeBlanc. 

"Mr. Speaker, we will fix the obvious ethical breach of the previous government," he retorted, the Liberals calling out their appreciation for the quip, "by taking a series of appointments that were made inappropriately and putting them before the standing committees of this House. That is exactly how we are proposing to clean up the ethical mess left to us by the previous government."

The Liberals stood again to cheer, and the prime minister, standing with them, jawed inaudible words across the aisle and motioned slightly with his left hand for his rivals to keep it coming.