There's one question Prime Minister Justin Trudeau can be certain reporters will ask him on his first official trip to China this week.

"Did you bring up human rights?"

And it won't stop there.

"Did you bring up human rights forcefully enough? Frequently enough? Are you putting trade before human rights?"

Journalists have asked variations of these questions for decades, grasping for some way to ensure politicians aren't abandoning principle as they try to build ties to countries, such as China, with a record of high-profile human rights abuses.

Reporters might be asking about a Canadian who has been detained or referring to broader questions about how the country treats its citizens.

Either way, reporters often find the answer to "the human rights question" wildly unsatisfying. The answer is inevitably some variation of "Yes, of course," without much sense of the intensity or efficacy of the discussion.

So, what really happens behind closed doors?

Prime Minister Justin Trudeau met with Chinese President Xi Jinping for bi-lateral meeting at the G20 Summit in Antalya, Turkey last November. (Canadian Press)

Avoiding ultimatums

Trudeau leaves Monday for a week-long tour, where he'll try to expand Canada's economic relationship with China. His stops will include Beijing and Shanghai.

Rule No. 1 for Canadian officials, according to former Canadian ambassador to China David Mulroney, is to avoid being told "No" right off the bat.

"People think we should just have our minister or the prime minister pound on the desk and make it clear. That's very satisfying for about two minutes and then you realize the door is shut and there's no further possibility."

"What you're trying to do is nudge, push, edge the issue towards a positive conclusion."

Most progress happens over the medium to long term, said Mulroney, who is now president of St. Michael's College at the University of Toronto. When you're dealing with individual cases, like trying to secure the release of someone who has been imprisoned, Mulroney suggests it can require some creativity.

David Mulroney, former Canadian ambassador to China, says, 'What you're trying to do is nudge, push, edge the issue towards a positive conclusion.' (Pawel Dwulit/Canadian Press)

He points to one case he worked on, where a Canadian woman's Chinese husband was imprisoned and likely being beaten up. Mulroney wanted to help but felt that because the man wasn't a Canadian citizen, if officials brought up the case directly, China would tell them to butt out.

Instead, Mulroney said he opted for a "softer and more friendly" approach.

Canada's health minister at the time, Leona Aglukkaq, was visiting China. He suggested she raise the case with her Chinese counterpart by framing it as a question of whether the man needed medical attention. Mulroney also advised her to wait until the two were talking privately, on their way to lunch.

"I said … 'Just say, "Look, I don't want to deflect us from our conversation about health issues, but I did want to raise this case and ask if you would be so kind as to investigate it as a physician."' And we actually did find out that the person did ask about the case."

He said eventually the man was released. Mulroney believes that conversation helped make it happen.

Can outsiders make a difference?

When it comes to big-picture human rights issues such as the rule of law, the former head of the Canadian Consular Service questions how much impact a country like Canada can have.

"Change does not come because of outside pressure," said Gar Pardy, who was also ambassador to several countries. "We do this kind of thing to make ourselves, I think, feel good when we say these things to another government."

Gar Pardy, former foreign affairs department director-general of consular affairs, says, 'Change does not come because of outside pressure.' (Fred Chartrand/Canadian Press)

That said, Pardy believes Canada's prime minister still faces internal pressure to raise human rights concerns.

"Canadians expect Mr. Trudeau to say something in this area and try to be effective about it."

He also believes that change is more likely to happen away from higher profile meetings like prime ministerial visits.

Canada used to hold regular meetings with Chinese officials, he said, where specific issues could be discussed. He argues that's a better way to have more detailed discussions.

"The possibility of re-establishing that kind of annual dialogue with the Chinese, I think, would be much more effective rather than an occasional visit with the minister or prime minister, which in effect [is] 'Did you raise human rights?' 'Yes, I raised human rights.'"