Ready to rumble: Liberal ministers brace for critics' grilling in the House of Commons

Canada's political parties are preparing to start a new session of Parliament and run the daily gauntlet of question period, when opposition MPs fire out questions and hold the government to account.

Each opposition party leaderhas enlisted a team of critics to shadow the Liberal cabinet ministers, scrutinizetheir policies and keepthem on their toesin the House of Commons.

Here's a look at some of the personalities Canadians will see battling over key ministerial files.

(For the purpose of these comparisons, CBCNews looked mostly at the three main national political parties. Whilethe Bloc Qubcois will have more time than the NDP to grill ministers because it has a higher seat count,the BQ runs candidates only in Quebec and its MPs tend to ask questions solely onissues related to Quebec.)

The leaders: TrudeauScheerSinghBlanchet

It will be a differentdynamic in the House this time for the re-elected Liberals, as Prime Minister Justin Trudeau returnsto Parliament with a minority government and Conservative Leader Andrew Scheerworks to throw his toughest political punches while dealing with internal party critics and a push for a new leader.

After a nasty election campaign, many observers will be watching to see if that tone carries over to the House of Commons, or if the daily duels are more civil. After losing 15 seats, NDP Leader Jagmeet Singh is now relegated to fourth spot behind BQ LeaderYves-FranoisBlanchet, who will take his seat in the Commons for the first time. That means Singh will have lower priority when it comes to asking questions in question period, and less speaking time in the House of Commons.

The deputies:FreelandAlleslevBoulerice

Trudeau namedChrystia Freeland deputy prime minister the first deputy PM since Anne McLellan in Paul Martin's government. (Stephen Harper never appointed one.)She's also in charge of the challengingintergovernmental affairs file, tasked with strengthening national unity and leading talks with the provinces and territories on complexissues like health care, pipelines andclimate change at a time of deep political dissatisfaction in the West.

Conservative MP Leona Alleslev, a former Liberal who crossed the floor, will serve as Scheer'sdeputy leader. Alexandre Boulerice will act as Singh's right hand.

House leaders:RodriguezJulianBergen

Losing their majority government means the Liberals no longer get to call all the shots. Instead, they must engage in tough negotiations with opposition caucuses to advance their legislative agenda. The House leaders for each party are in charge of parliamentary procedure andday-to-day business in the House, including negotiating the timing of debates and votes.

Government House Leader Pablo Rodriguez will be thrashing things out withConservative House Leader Candice Bergen,NDP House Leader Peter Julian and Bloc Quebecois House Leader Alain Therrien.

Finance: MorneauPoilievreJulian

Perhaps no portfolio is more important than finance. The department decides how Canadians' tax dollars are spent and could be tasked with steering the economy through rough times ahead.

Finance Minister Bill Morneauis one of a handful of ministers Trudeau has kept on the same file since 2015. He'll be grilled by the same opposition critics he faced in the 43rd Parliament:Conservative finance critic Pierre Poilievre and NDP financecritic Peter Julian.

The next budget will be Morneau's most important yet, as it must win the confidence of the House to ensure the minority government survives though no party likely has an appetite for a snap election right now.

Public Safety: BlairPaul-HusHarris

Public Safety is one of the biggest, most important government portfolios; it was presided over by one of Trudeau's most trusted ministers, Ralph Goodale, until he was defeated in the election. Former Toronto Police chief Bill Blair is stepping up to stickhandlesome important files: national security andborder control, and overseeing organizations such as theRCMP, the Canada Border Services Agency, the Canadian Security Intelligence Service and Correctional Service Canada.

Delivering on the government's controversial promise to ban semi-automatic rifles and empower cities to ban handguns is likely to be a top priority for Blair. Monitoring his every move will be Conservative public safety critic Pierre Paul-Hus and NDP public safety critic Jack Harris.

Foreign Affairs: ChampagneO'TooleHarris

Freeland remains the lead minister on the crucial Canada-U.S. relations file, dealing with the Trump administration on key projects such as getting the trilateral trade deal with the U.S. and Mexico approved in all three countries.

But new Foreign Affairs MinisterFranois-Philippe Champagne will still be kept busygiving voice to the Canadian government's positions on international matters, fromglobal conflicts to consular cases. The tense bilateral relationshipwith Chinais a pressing priority; Canadians Michael Kovrig and Michael Spavorare still being held inChinese prison cellsa year after their initial detention. Conservative MP Erin O'Tooleand the NDP's Jack Harris will be Champagne's critics.

Justice: LamettiMooreGarrison

David Lamettihas a dual role as minister of justice and attorney general of Canada, overseeing Canada's justice system and providing legal services to the government. He is tasked with ensuring all government legislation is constitutional.

Lamettican expect a lot of opposition interest in the matter of whether he intends to provide a remediation agreement to SNC-Lavalin, which could effectively halt criminal proceedings against the Quebec-based engineering company. Lametti has described deferred prosecution agreements a "legitimate legal option" but has said he will not make any decision because of ongoing litigation involving the company. (SNC-Lavalin's legal situation was, of course, at the heart of the political scandal that consumed much of Trudeau's first term and cost him two cabinet ministers.)

Lametti will face questions in the House of Commons from Conservative justice critic Rob Moore and NDP justice critic Randall Garrison.

Indigenous Services: MillerVidalSingh

Trudeau has stated that reconciliation and improving relations with Indigenous persons is a top priority for the government, and improving access to services for First Nations, Inuit and Mtisis critical to fulfilling that promise. Among the pressing tasks facing the governmentare working out a compensation program for First Nations children affected by the on-reserve child welfare system and providing clean water on reserves. Conservative MP Gary Vidal will serve as his party's Indigenous services critic.NDP Leader Jagmeet Singh appointed himself to the critic's role.

Immigration: MendicinoKentKwan

Marco Mendicino will step into the hot seat as the new minister of immigration, refugees and citizenship, overseeing the complex system that sets immigration levels,grants citizenship and manages the refugee intake. It also handles Canadians'travel documents, such as passports.

One of the most pressing problems for the government on this file is managing the flow of asylum seekers entering Canada outside official border points a trend that has generated considerable criticism for the Liberals. Conservative MP Peter Kent is his party's new immigration critic, while Jenny Kwan returns to the critic's role for the NDP.

Environment and climate change: WilkinsonFindlayCollins

Addressing climate change emerged as a top election issue, and it will continue to be a priority debate in the coming Parliament. Expect Environment and Climate Change Minister Jonathan Wilkinson to be on his feet a lot,explaining howthe Liberal government will deliver on a plan to cut emissions while it proceeds with plans to expand the Trans Mountain pipeline.

Some critics say the Liberal environmental plan is not robust enough, while others insist a central component of it, afederal carbon tax, will cost Canadian families and harm the economy.Kerry-Lynne Findlay will serve as the Conservative critic she succeeds Ed Fast, a former cabinet minister who declined a critic's post over concerns about Scheer's leadership. Laura Collins, a former city councillor and instructor at the University of Victoria, is the NDP's critic.

Health: HajduDaviesGladu

New Health Minister Patty Hajdu will be kept busy with issues ranging from the opioid crisis to taking the first steps toward a national pharmacare program. She also willbe tasked with working on a new health funding formulawith provincial and territorial leaders, who are pushing for a significant increase in federal transfers. Conservative MP Marilyn Gladu will keep her on her toes, along with NDP critic Don Davies.

Natural Resources: O'ReganStubbsCannings

The natural resources file comes with built-in controversy, as the battle rages over reconciling the need to protectthe environment with oil and gas development and transport. The portfolio also is responsible for promoting new energy sources (such as nuclear) and other sectors like forestry and mining.

But job number one for new Natural Resources Minister Seamus O'Regan will be to get a pipeline built to ease political tensions in Alberta and Saskatchewan, where the Liberals were shut out in the last election. O'Regan can expect a daily grilling from Conservative natural resources critic Shannon Stubbs and NDP critic Richard Cannings.

CBC coverage of Thursday's throne speech

Rosemary Barton hosts special coverage of the Speech from the Throne beginning at 2 p.m.ET on CBC News Network, CBCnews.ca and Facebook. Tune in to CBC Radio One for coverage of the speech starting just before3:30p.m. ET. And find analysis and reaction on CBC News Network's Power & Politics at 5 p.m. ET, World at 6 on CBC Radio One and on CBC TV's The National at 10 p.m.