Wrapping up what he described as a "busy" fall on Monday, the prime minister could point to a national deal on climate change, a free trade agreement with Europe, decisions on pipelines and official visits to the United Nations, China and Cuba.

And in the 20 minutes allotted to reporters for questions, Justin Trudeau would be asked about Donald Trump, federal funding for health care, electoral reform and his government's efforts to "de-colonialize" federal laws that apply to Indigenous Canadians.

But the news of the day would be Trudeau's involvement in the Liberal Party of Canada's fundraising.

Which is in keeping with the fall sitting his news conference was meant to cap.

In a season of weighty matters and potentially profound decisions — a pipeline to the West Coast, a price on carbon, the vague possibility of a new electoral system — there has been the constant, nagging hum of ethical concern.

Interim Conservative Leader Rona Ambrose called the Liberal fundraising controversy an 'ethical mess' Monday. (Sean Kilpatrick/Canadian Press)

From Sept. 19 through Monday afternoon, 29 of 51 question periods included queries about Liberal fundraising.

The Conservatives and New Democrats have dwelled most enthusiastically since mid-October. Over the past 34 question periods, the opposition has failed to ask about fundraising only a half-dozen times.

Trudeau muddies the waters

To recap: Liberal ministers, including the prime minister, have been participating in fundraisers at which relatively small groups of people pay up to $1,500 to enjoy the company of a member of cabinet.

Critics find these Liberal events difficult to square with the policy in the prime minister's own guide for ministers that says, "There should be no preferential access to government, or appearance of preferential access, accorded to individuals or organizations because they have made financial contributions to politicians and political parties."

Trudeau further muddied the waters on Monday.

In November, the executive director of the Liberal Party said, "Fundraising events are partisan functions where we do not discuss government business."

But, in response to a question on that distinction, Trudeau seemed to acknowledge attendees have approached him to discuss topics other than sports or the weather.

"Any time I meet anyone, you know, they will have questions for me or they will take the opportunity to talk to the prime minister about things that are important to them," he said.

The Prime Minister's Office later pointed out Trudeau hadn't said "government business" was discussed. "There is an important difference between listening to someone and engaging in a detailed policy discussion," a spokesman said.

Any time I meet anyone, you know, they will have questions for me or they will take the opportunity to talk to the prime minister about things that are important to them. - Prime Minister Justin Trudeau

There are nuances that might be explored here — What constitutes government business? — but fine distinctions likely won't make this go away.

The ethics commissioner has been asked to review the matter, but even if no law was broken, the Liberals will probably still have something of an "ethical mess," as interim Conservative Leader Rona Ambrose called it in the House of Commons on Monday.

Trudeau says donors don't hold sway

Trudeau's assurance on Monday was that nothing he hears from party donors is decisive.

But if it were as easy as believing a politician's assurances that nothing untoward is occurring, there would be no need for any restrictions on political fundraising.

The counter-argument would be $1,500 — a tiny fraction of the cost of a national election campaign — is probably not nearly enough to sway a government's decisions.

But then there are obviously some people who think there is some benefit to being in a minister's midst.

The Liberal defence has been to boast of the government's openness to all Canadians and to remind everyone of the strength of existing fundraising laws — over the past three months, government House leader Bardish Chagger has used the word "strictest" to describe the rules on 53 occasions.

Government House leader Bardish Chagger used the word 'strictest' 53 times this fall to describe the existing fundraising laws. (Adrian Wyld/Canadian Press)

On Monday, NDP MP Alexandre Boulerice announced he'd soon have a bill that would put the prime minister's guidelines on "preferential access" into law.

That could mean banning ministers from all fundraising. And maybe that's where this debate is headed. Though perhaps at that point it will be tempting to ban all MPs and candidates from fundraising.

The prime minister has acknowledged there are "questions" about his party's fundraising habits. At the very least, the controversy has raised a potential weak spot in the existing law.

But his government hasn't yet been moved to change anything in response.

It could be the Liberals would simply like to raise as much money as possible. Or that they believe they've done nothing wrong.

And it could be that this will eventually go away. Back in August, the Liberals were trying to escape Health Minister Jane Philpott's car service bills. That seems like a distant memory now.

Will Liberals tire of playing defence?

However persistent the questions, Liberal support in public polls has remained robust.

The Liberals might even be satisfied to have the opposition use precious time on political fundraising, as opposed to any of the issues that might actually decide the next election.

NDP MP Alexandre Boulerice plans to introduce a bill that would tighten fundraising rules. (Sean Kilpatrick/Canadian Press)

Back in April 2008, the Conservative Party of Canada's offices were raided by Elections Canada in connection with the "in-and-out" campaign spending scheme. Five months later, the Conservatives won 16 more seats in besting Stéphane Dion's Liberals.

If a link between fundraising and action is never established and if the government can avoid seeming otherwise out of touch with those who can't afford to pay hundreds of dollars to hang out with the finance minister, the Liberals might be able to withstand more weeks or months of questions.

But they might decide it's not worth the risk and that protecting the credibility of the political system from suspicion is itself a big deal, like free trade, pipelines and the other issues Trudeau tried to highlight Monday.

If the questions continue in the new year and the Liberals ever tire of playing defence, they could try leading.