Friday marked the one month countdown to Parliament resuming and voters going to the polls in a pair of byelections in Manitoba and Quebec.

With the sun starting to set on the Canadian political summer, here's everything you need to know about the key political happenings between now and when MPs return to Ottawa.

Plus, what political insiders, analysts, and pollsters are saying about party fortunes and strategies heading into the fall season.

Byelections collide with Parliament's kick-off

The summer political news cycle will be starting and ending with federal byelections.

After the shocking Conservative victory in Toronto – St. Paul's in late June, two more byelections have been called for Sept. 16. One is happening in Quebec to fill former Liberal MP David Lametti's seat, and the other is in Manitoba, to replace former NDP MP Daniel Blaikie.

Sept. 16 also happens to be the first day of the fall sitting of Parliament, setting up for an epic day of overlapping political storylines.

Given how intensely scrutinized Prime Minister Justin Trudeau's leadership was after the Liberals lost a long-time stronghold, and how he dug-in vowing to spend the summer listening to what Canadians are looking for, the stakes are high for the party heading into these byelections.

"I found this summer to be a fascinating political season," CTV News political commentator Scott Reid said Wednesday on The Vassy Kapelos Show.

"Because it began with the loss of the byelection in Toronto – St. Paul's, which felt like a political earthquake, was treated like a political earthquake, and everyone in politics reacted like there had been an earthquake, except the government and the prime minister."

Justin Trudeau

Reid said heading into the pair of September races the Liberals remain 20 points behind in the polls, and the question of what they intend to do differently is still hanging over Trudeau.

"As far as I can tell, the government's answer is nothing."

There's also been some interesting political dynamics playing out between the Conservatives and New Democrats this summer that are set to spill into the byelections.

Last month, Conservative Leader Pierre Poilievre launched attack ads against NDP Leader Jagmeet Singh, after the New Democrats dropped their own in June. 

On the question of advertising, Summa Strategies' Tim Powers questioned why Trudeau's team has still not heeded calls to launch advertising efforts against Poilievre.

"They don't have the resources the Conservatives do, but use some resources to do this, because the hole is getting deeper and deeper," he said Wednesday on The Vassy Kapelos Show.

Who is running for a seat in the House?

As for who is running to join the more than 300 elected officials heading back to the nation's capital in September, here's a rundown of the candidate roster so far.

There's already a full slate of major party candidates on the ballot in LaSalle-Emard-Verdun, Que. and again, thanks to electoral reform advocacy group the Longest Ballot Committee, dozens of independents.

The Liberals are running Montreal councillor Laura Palestini and the Conservative candidate is a small business owner named Louis Ialenti. NDP are running another city councillor, Craig Sauve, while the Bloc Quebecois has put up a staffer with the same last name, Louis-Philippe Sauve.

Jagmeet Singh

The Green candidate is activist and political adviser Jency Mercier, and new addition the Canadian Future Party is running entrepreneur Mark Khoury.

Heading west to Elmwood-Transcona, Man., the ballot roster remains a bit sparser. There have yet to be any influx of independents, and while the Liberals have named their candidate – retired teacher Ian MacIntyre – as of Friday, he was not among Elections Canada's list of confirmed contenders.

Pollsters have indicated this race may be shaping up to be more of a showdown between the incumbent New Democrats and the Conservatives who are angling to overtake another stronghold.

Conservative hopeful Colin Reynolds is hoping his experience as a unionized electrical worker helps lock in blue-collar workers, though the NDP candidate and local business improvement leader a series of endorsements from labour leaders, including from her opponent's union. 

The Green candidate is community organizer Nicolas Geddert, while the Canadian Future Party has tapped a public servant to run.

Nanos Research chief data scientist Nik Nanos said these ridings will be a first test for the fledgling political party, while noting that as of his latest tracking, "only about one out of every 10 Canadians are undecided."

Could a shuffle come before then?

Before these byelections happen, there's a series of sizeable other political events on the calendar. From caucus and cabinet retreats, to the much-rumoured shuffling of Trudeau's front bench.

Here's why these gatherings are significant, and what the political objectives of them are.

Let's start with what, arguably, would have to come first: a cabinet shuffle.

This is still entirely speculative, and almost predictably the question of the late summer each year. No plans to visit Rideau Hall have been confirmed, but if it's going to happen, all eyes are on the week ahead.

The timing expectation here is because the prime minister has already scheduled his end-of-summer cabinet retreat – where he convenes a series of closed-door meetings with his ministers to plot strategy and policy – for Aug. 25 to 27 in Halifax, N.S.

Convention would be that Trudeau would want the go-forward team in those meetings, not ministers making decisions on files they wouldn't then be responsible for in a few weeks.

While a lot of words have been spilled about how a shuffle could be seen as a reset for the minority Liberal government, it's a move Trudeau has tried a few times before.

This time, politicos from all sides of the spectrum are doubtful of the overall impact a cabinet shake-up would have.

"Canadians have sent the food back to the kitchen so many times, and Justin Trudeau keeps coming up with a smile on his face with the same plate again, saying, 'here it is, it's been microwaved, you should love it this time,'" said Syntax Strategic partner and former NDP communications director George Soule on Monday's episode of The Vassy Kapelos Show.

"The house is on fire, so it doesn't matter how many times you rearrange the chairs at the cabinet table, you're not going to put the fire out."

Spark Advocacy's Sabrina Grover said in the same episode that Canadians don't tend to know one cabinet minister from the next.

In her view, as someone who has run for the party previously, "that's not the change that's needed in order to reignite the Liberals, in order to reintroduce them to Canadians, in order to tee-up either this parliamentary session or the 2025 election."

Noting previous shuffles have been used to either provide cover for moving out underperformers, or excuse ministers who have decided not to run again, Crestview Strategies partner and former Conservative campaign manager Ashton Arsenault said beyond that utility, voters likely aren't paying attention.

"Change is a powerful motivator, and once that genie is out of the bottle, it's nearly impossible to stuff it back inside," he said on Tuesday's episode of The Vassy Kapelos Show.

Pierre Poilievre

The other pre-return-to-Parliament tradition coming up are caucus meetings. The Liberals are expected to fly out to British Columbia for theirs, in early September.

The Conservatives and New Democrats are also likely well into planning pre-Parliament caucus meetings.

Neither have yet to announce where they'll be convening their teams, though if past is prologue, Poilievre's MPs may end up meeting in a room on the Hill, while Singh's MPs descend on a riding they're looking to make gains in.

Big picture, as the parties plot out the remaining weeks of their summer tours, Angus Reid Institute President Shachi Kurl said something seismic would have to happen in order to see the current political narratives and polling fortunes change with the season.

"It will have less to do about what the Liberals are doing, and more to do with external factors," she said on Tuesday's episode of The Vassy Kapelos Show.

"At his stage, after this much longevity, what has happened is… both opposition and support are baked-in."