With the federal election less than a week away, two incumbent candidates in Ottawa have erected unusual issue-based campaign signs that are neither Liberal red nor Conservative blue.

Black signs have cropped up along roadways in Carleton riding with messages such as "Support Small Business" and "Vote Pierre Poilievre".

It's the first time in six campaigns that Conservative Pierre Poilievre has gone beyond the typical party sign with this name on it.

"The causes I'm championing — to defend small businesses against Liberal tax hikes, to protect taxpayers against higher costs, to let people get ahead — transcend all party colours in the sense that people from all parties are affected by it," he told CBC News.

Conservative candidate Pierre Poilievre and Liberal candidate Catherine McKenna, both incumbents, have debuted new signs that highlight election issues rather than party colours. 0:54

Poilievre is again being challenged by Liberal Chris Rodgers, whom he beat by three percentage points in 2015, as well as the NDP's Kevin Hua, Green Party's Gordon Kubanek and Alain Musende of the People's Party of Canada.

Poilievre suggested a coalition between Liberals and NDP might be the outcome of Monday's election, and not to every voter's liking.

"I want to let them know that even if they had a prior political allegiance, they can vote for me to stop those tax increases and make their lives more affordable so they can get ahead."

McKenna's six signs

Voters in the city core, meanwhile, might have noticed unusual signs from the Catherine McKenna campaign with simple statements such as "'Vote for Our Climate" in both languages on a turquoise placard or "Vote to End Poverty" on a yellow sign.

Other signs carry messages about supporting public service jobs, gun control, and abortion rights.

Catherine McKenna's campaign has put up six new signs as the election nears its end, none of which is Liberal red. (Hillary Johnston/CBC)

"These signs are intended to pop," explained McKenna, noting she has many red Liberal signs across the riding. Those traditional signs compete with those of NDP challenger Emilie Taman, Conservative Carol Clemenhagen, Angela Keller-Herzog of the Greens, and Merylee Sevilla of the People's Party of Canada.

Like Poilievre's, the signs in Ottawa Centre are McKenna's own initiative and approved by her own agent rather than her political party.

McKenna also suggests the Conservatives might form the government instead of her Liberals.

"The point is to differentiate from all the signs that are out there, to cut out the noise, to get to what is really at stake. This is a really important election. These are really important issues," she said.

Loyal to party lines, both say

"I don't recall seeing signs like these before," said Steve White, a political science professor at Carleton University.

Local campaign signs will sometimes emphasize the party leader, however, or play up the candidate him or herself, he said.

Signs like this one have cropped up on busy roads in Ottawa Centre during the final week of the 2018 campaign. (CBC)

White wouldn't speculate about the strategy behind Poilievre's and McKenna's new signs, and says it's hard to know what impact they will have.

"There's very little research on the impact of campaign signs on the vote in Canada," White said.

Asked if his black signs are an effort to depart from the central campaign, Poilievre says the messages are in line with the Conservative platform.

"I'd say it's complementary," Poilievre said.

Similarly, McKenna said she's not trying to distance herself and no one questions she's a Liberal.

"I wear red all the time," she said.