SURREY, B.C. -- Inside a colourful candy shop in a bustling Vancouver suburb, Andrew Scheer and Kerry-Lynne Findlay marvelled at delicate British chocolate bars, chewy Red Vines and an edible Monopoly board.

The Conservative leader and byelection candidate weren't shopping just to soothe a sugar craving. They were making a political point about small business taxes, an issue they're pushing to be front and centre in South Surrey-White Rock.

"People are saying, 'I'm paying a lot higher taxes than I was before. I'm being called a tax cheat because I'm an entrepreneur with a small business,' " said Findlay, 62, a former national revenue minister.

The riding is one of four across Canada where a byelection will be held Monday, but it's anticipated to be the closest race. Conservative Dianne Watts won by just 1,400 votes over the Liberal candidate in 2015, while the NDP placed a distant third.

The vote arrives midway through Prime Minister Justin Trudeau's term and it's expected to test his popularity, as well as the potential of rookie leader Scheer, ahead of the 2019 election. Both men have visited the riding twice and both have suggested the outcome will indicate whether the Liberal surge of 2015 is continuing or waning.

"Two years ago, in the election, Canadians didn't randomly or suddenly change who we are," Trudeau said at a recent rally to support Liberal candidate Gordie Hogg, 71.

"We have always been progressive, forward-thinking, open, compassionate, ambitious people," he said. "It was just about getting a government that recognizes that."

South Surrey-White Rock has older, wealthier and whiter demographics than other ridings in Surrey, which is the fastest-growing city in Metro Vancouver. It's home to a picturesque waterfront and an array of restaurants, shops and other small businesses.

In July, Trudeau's government announced plans to close loopholes that it said have allowed high-earning business owners to avoid higher taxes. The measures included changes to "income sprinkling," which allows owners to split income among family members.

After a backlash, the government said it would cut the small business tax rate from 10.5 per cent to nine per cent by 2019.

Hogg said he and Trudeau are committed to cutting taxes for small businesses, while the Conservatives voted against a tax cut in 2015 for "middle-class" Canadians earning between about $45,000 and $90,000 a year.

"To me, their record is more important than their rhetoric," said Hogg. "This byelection is about electing the strongest positive voice for our community, and only Justin Trudeau and I have a positive plan to strengthen our middle class and offer real help for families."

The seat became vacant after Watts resigned to run for leader of the B.C. Liberal Party, an informal coalition of federal Conservatives and Liberals.

Byelections will also be held in Battlefords-Lloydminster in Saskatchewan, previously held by the Conservatives; Bonavista-Burin-Trinity in Newfoundland, a Liberal seat; and Scarborough-Agincourt in Ontario, also won by the Liberals in the last election.

In South Surrey-White Rock, Hogg has name recognition and deep roots. He was White Rock mayor for 10 years before being elected to the B.C. legislature for two decades. Findlay, meantime, represented Delta-Richmond East in Parliament from 2011 to 2015.

Asked about her connection to the riding, Findlay said her parents lived in the community and she has also lived there at various points, including after she was widowed at 34 and was raising her children alone. She said she moved to White Rock this summer.

The NDP candidate is Jonathan Silveira, 40, a real estate agent and founder of advocacy group Surrey Kids Matter. He said the byelection was an opportunity to train new volunteers and strengthen relationships, but added he was serious about winning.

"There are two big sharks fighting here. I am not afraid of the fight as well," he said.

New Democrat Leader Jagmeet Singh has not joined Silveira in the riding.

Trudeau's recent rally with Hogg in Surrey drew hundreds. Some were not local voters, however, including a Syrian refugee who said she wanted to thank Trudeau, and a visitor from Singapore who wanted to see the famous Canadian politician in person.

The prime minister is pictured alongside Hogg on campaign signs, indicating confidence among Liberals in Trudeau's popularity.

Scheer and Findlay, however, said they've heard from people who have "buyer's remorse" after voting Liberal in 2015.

It's hard to predict a general election based on byelections, Scheer added, because the latter generally have lower turnouts, and local issues become amplified over national ones.

"But I think we would love to send a signal, mid-term, that what the Liberals have been doing for Canadians isn't working."