OTTAWA -- When Rona Ambrose emerged from a Conservative caucus meeting 18 months ago as the party’s new interim leader, the surrounding MPs chanted her name. Sort of. They mis-pronounced it Roh-na, like the hardware store, rather than Ron-na, like Donna.

They won’t get it wrong now.

She's leaving Parliament on a high note: Ambrose has guided the party's rebuilding after a crushing defeat at the polls, while avoiding any major missteps.

The Oct. 19, 2015 election was a dark day for a party that had been in power nearly 10 years. They lost 60 seats and got shut out of both Toronto and Atlantic Canada following a nasty campaign plagued with leaks and infighting. Worse, they lost to Justin Trudeau, the man they'd spent two years trying to paint as an intellectual lightweight.

Weeks later, the caucus elected Ambrose as interim leader -- a heavy counter-balance to Stephen Harper's cold aloofness. She promised to lead a strong opposition, but one that was "extremely constructive." She wouldn't say whether her selection marked a change in tone, but a number of re-elected MPs acknowledged they'd been too mean-spirited compared to Trudeau's "sunny ways" campaign.

An interim leader has to walk a fine line: she must hold the caucus together and maintain the support of party members, without setting major new policies the more permanent leader may change. Under Ambrose, the Official Opposition hewed closely to its traditional principles, keeping its focus on criticizing government spending, deficits and what it calls Liberal entitlement.

Conservative House leader Candice Bergen says Ambrose never treated the interim position as a placeholder.

"From the onset she gave everything to the role, and in doing so has led and unified a caucus and party through what many would acknowledge could have been a very difficult time," Bergen said in her tribute to Ambrose on Tuesday.

"All the while, she's consistently shown her sharp intelligence, keen sense of humour, and her genuine kindness and nurture."

The Conservatives will choose their next leader on May 27.

'Dark period'

Ambrose's success as the interim leader stands in contrast to an early failure in cabinet. After she'd spent a year-and-a-half as an opposition MP, Stephen Harper led the Conservatives to their 2006 election win. Ambrose was named environment minister, making her the youngest-ever female cabinet minister.

It was a challenging portfolio in a party skeptical about the impact of climate change and of the international agreements the preceding government signed. The Conservatives were met with serious criticism from environmental advocates. Ambrose was shuffled out of the file a year after taking it on, moving to the low-profile intergovernmental affairs role.

It was a difficult time for the former Alberta civil servant, long-time friend Michele Austin says.

"That was a particularly dark period for, but ... ultimately, even though it was awful, she has learned so much from it and become so much better by going through it," said Austin, who served as Ambrose's chief of staff from 2011 to 2013.

Eventually, Ambrose worked her way back to more prominent files. In 2010, she became the public works minister, which -- while less prominent outside Ottawa -- is the head of the department in charge of billions in government procurement. That file also included the massive national shipbuilding procurement strategy, a $38-billion project praised at the time for how the contracting was handled.

At the same time, Ambrose served as status of women minister -- another difficult portfolio in a Harper government. But she raised eyebrows when she voted in favour of a private member's motion to study when life begins, seen as a back-door way to re-open the abortion debate. She later said it was because she opposes sex-selective abortion.

Austin, chief of staff at the time, called it an awful night.

"These are the kinds of things that end up haunting you and your career," Austin said.

"That issue is silo'd as a social conservative, old-school issue because it's easy to paint her with that brush. There are just as many women who are interested in both sides of that debate.... She felt that Parliament was in a position to have a decent, constructive discussion about it, but it just became an overtly political issue as it always does and she ended up vilified for it."

In 2013, Ambrose became health minister. There she butted heads with health experts for opposing safe-injection sites, and criticized her own department for approving prescription heroin for some addicts, despite evidence the programs saved lives.

The Liberal government changed course on both measures, allowing for new safe-injection sites and overturning a ban on doctors prescribing pharmaceutical-grade heroin.

'They have what it takes'

MPs focused in their tributes on Ambrose's work on women's rights, and her collegiality. Green Party Leader Elizabeth May credited Ambrose for being likeable even when the two discussed the Conservatives' position on the Kyoto Protocol.

Austin says Ambrose fought hard at the cabinet table to improve the number of women getting federal appointments, particularly on the bench in Alberta (something another former Conservative official confirmed).

"She never went in with numbers. She never said we need to have 15 men and 15 women. She just asked the question, 'Where are the women,’" Austin said.

Ambrose spoke proudly of her work on women's issues during her final speech in Ottawa Tuesday morning. She noted the party's efforts to raise awareness about the number of Yazidi women forced into sexual slavery, as well as her work spearheading the UN declaration of the International Day of the Girl.

Ambrose says she plans to stay involved in politics. She promised to lead the charge to encourage more women to run for the Conservative Party, whose candidate roster in 2015 was 80 per cent men.

"Our caucus and our party is stronger with capable, strong, talented women on our team," Ambrose said in her speech to the Canadian Club of Ottawa Tuesday morning, singling out Bergen, leadership candidate Lisa Raitt and infrastructure critic Dianne Watts, among others.

"They're amazing leaders. But I want to make an important point. I didn't elevate them to fill a quota," she added.

"They have what it takes to compete. In fact, all of the women in Parliament do."

Ambrose said she's incredibly optimistic about the party's future.

"We are strong, focused and united. And there was no guarantee that it would be this way. And now we have clearly shown that Justin Trudeau can be beaten in 2019."