British Columbia's new Attorney-General is a former lawyer who built an uncompromising public profile with his searing criticism of police and government agencies he felt had failed the province's disadvantaged.

In politics, David Eby went on to become a giant killer, defeating former premier Christy Clark in her own riding in 2013 and later sharpening his barbs to skewer Liberal initiatives ranging from housing to transit to liquor distribution.

This latest job will require him to reconcile his past crusading efforts for the downtrodden with a more measured approach as he handles a portfolio that encompasses the province. He will inherit a full plate of complicated issues, ranging from justice reform to several legal cases such as a constitutional challenge to the province's rules against private health care.

Story continues below advertisement

Josh Paterson is executive director of the B.C. Civil Liberties Association, a job once held by Mr. Eby. Mr. Paterson said Mr. Eby's committed style will be in sync with the needs of his new job.

He said there is a lot of necessary "shaking up" ahead for the justice system in B.C.

"That takes a minister and a government who are going to be willing to show some real leadership and bring change that people in B.C. have been seeking in terms of how the justice system operates," Mr. Paterson said.

"Being strong in advocacy is a good quality for a cabinet minister. We've said today there are all kinds of different things that need fixing in the justice system. Those things are difficult to do. They require a careful approach, but also an approach that is strong and committed to doing things."

Mr. Eby's BC Liberal critics question whether he will bring that careful approach.

The former governing party, plunged into opposition for the first time in 16 years, is relishing the prospect of invoking Mr. Eby's past in advocacy.

As Mr. Eby took his cabinet oath this week, the Liberal caucus targeted him with a tweet recalling that the president of the Vancouver Police Union, once declared that Mr. Eby "never let the facts or context" interfere with a "smear campaign" of Vancouver Police. The issue, at the time, was the police shooting of Paul Boyd.

Story continues below advertisement

Liberal MLA Jas Johal elaborated on Wednesday in a statement: "David Eby has a long history of criticizing law-enforcement officials and making misleading statements about women and men in uniform. David Eby wrote a book on how to sue the police, criticized police activities at the 2010 Olympics, and his anti-police activism has drawn sharp rebuke from the head of the Vancouver Police Union."

"Now [Premier] John Horgan has put someone with a long track record of fighting the police in charge of upholding the law."

Mr. Eby, who turns 40 later this week, was unavailable for comment on Wednesday because he was attending the first NDP cabinet meeting.

In an April interview with The Globe and Mail, he said he welcomed the combative approach Mr. Horgan brought to politics.

Mr. Eby, a former minor-league hockey player, has said the "competitive edge" can get lost in politics.

"The desire to win can be something that's lost in discussions about policy. If you don't have the desire to win, you can talk about policy all day, but you're not going to form government," he said.

Story continues below advertisement

Mr. Horgan had hoped Mr. Eby, among other younger MLAs, would step up to seek the leadership when the job became open after the NDP lost the 2013 election many expected they would win under the leadership of Adrian Dix, who is now Health Minister. None of those MLAs did. Mr. Eby scrapped a planned leadership bid when he learned he was going to be a father.

Mr. Horgan, a Victoria-area MLA, was acclaimed as leader. He came to rely on a band of five MLAs, citing Mr. Eby among them. All are now in cabinet. Mr. Eby relished the responsibility, declaring it was a sign of confidence by Mr. Horgan.

"I always let John know I would take on whatever he sent my way and do the best I could on it," Mr. Eby said. "There were times I had to ask for backup because the housing file, for example, became quite consuming and other files started to drift a bit."

Mr. Eby, who was raised in Kitchener, Ont., has said he was imbued with a strong sense of justice by listening to his lawyer father denounce the "big, bad insurance companies."

He went on to become a lawyer himself, with an interest in human-rights issues nurtured by summer volunteer work for the Pivot Legal Society, which uses legal tools to address poverty and social exclusion.

Although he worked at the federal Justice Department upon his 2004 graduation, he happily went to work for Pivot for less pay – lured, he has said, by the society's creative use of the law to advance the interests of people without a voice in society. He worked on issues around police accountability and housing justice. At the civil-liberties association, he worked in these and other areas.

Story continues below advertisement

"He has a strong understanding of how laws and policies affect people who lack power within the system and especially those who are marginalized and live in poverty. That understanding, we hope, is good for all British Columbians," DJ Larkin, a lawyer with the Pivot Legal Society, said in an interview on Wednesday.

"As with any attorney-general, we know he will be acting in the best interests of the people of British Columbia – and that requires a measured approach."