A grassroots movement has been underway for years to "clean up" the radio waves around Quebec City, where shock-jocks unapologetically skewer anything that doesn't align with their populist conservative views.

In the wake of Sunday's bloody attack on a suburban mosque, that movement may be gaining some mainstream support.

The suspect in the attack, 27-year-old Alexandre Bissonnette, appears to have espoused what many consider to be far-right social and political views: he ridiculed the women's rights movement, backed U.S. President Donald Trump and trolled supporters of refugees.

Many of those opinions regularly get a sympathetic ear on radio poubelle, the French term for "trash radio."

Radio poubelle stations often air segments voicing concerns about Muslim immigration and the threat of Islamic terrorism — programming that leaves many local Muslims feeling alienated and misunderstood.

Couillard (left), local Muslim leader Salah Benrekik (centre) and Quebec City Mayor Régis Labeaume (right) address reporters the day after Sunday's deadly mosque shooting. Labeaume has called out talk radio for 'profiting from hate.' (Alice Chiche/AFP/Getty Images)

"You can't listen to it," said Mohamed Bouharras, who prays at the Quebec City Islamic Cultural Centre, the mosque that was attacked Sunday. "They don't have information about real Muslims. They don't ask Muslims about the real Islam."

As Quebec's political class soul-searches about its role in fostering fears of Islam, after years of debating questions of identity and religious accommodation, it has hinted the radio poubelle stations ought to do the same.

"A certain time comes when you have to call out the managers, the owners, the families of owners and above all the shareholders of the companies who create and sell hateful products," Quebec City Mayor Régis Labeaume told reporters Wednesday.

Earlier in the week, Labeaume criticized those who "profit from hate." The comments were widely interpreted in Quebec City as a broadside against its talk-radio culture.

Several stations — CHOI-FM, FM 93 and BLVD 102.1 — declined interview requests from CBC News.

Competitive, lucrative business

Talk radio is a competitive, lucrative business in Quebec City. There are five stations broadcasting a range of offerings, even though the Greater Quebec City area only has around 1.1 million residents.

The latest Numeris ratings had CHOI and FM 93 respectively at the top of the market. Both are heavy on talk-radio content.

Jeff Fillion, at CHOI, is the noon-hour leader. In November, Fillion wondered on air why Canada was welcoming Muslim immigrants.

Radio host André Arthur questioned a local newspaper's obituary of one of the mosque shooting victims. (Radio-Canada)

"We are ready to bring in all these people who don't have our values, values that are not ours, people who don't have any consideration for women," he said.

When the Quebec City Islamic Cultural Centre had a pig's head placed on its front step last summer, FM 93's Éric Duhaime derided those who called it a hate crime.

"Calm yourselves down," said Duhaime. "Where in the criminal code is it written that you don't have the right to give a pig's head … Maybe it was just a stupid joke."

One breaks rank, more to follow?

Quebec City's mayor is far from the first to question the editorial decisions of the likes of Fillion, Duhaime and the dean of radio poubelle, André "King" Arthur.

A long string of CRTC complaints has followed them from station to station. In 2015, more than 80 unions and community groups who work in the Quebec City area signed a "declaration for clean airwaves."

A separate coalition has maintained a website since 2012 that archives segments it finds offensive from the various poubelle shows.

The coalition members are anonymous. Many stations have been litigious with their critics in the past and the operators of the website — Sortons les radio-poubelles (Take out the trash radio) — fear lawsuits.

The coalition has begun circulating a letter to local advertisers, asking them to pull their support from the poubelle stations in the wake of the mosque shooting.

CHOI-FM radio host Jeff Fillion has made a long career courting controversy. (Tobin Grimshaw/Canadian Press)

But so far the radio poubelle hosts have been unbowed by the magnitude of Sunday's attack and subsequent calls for more tolerant public debate.

On his Tuesday show, Arthur criticized a local newspaper's obituary of Azzedine Soufiane, the 57-year-old owner of a halal grocery store who was among the six men killed in the mosque attack.

The paper, he told his listeners, had failed to mention Soufiane's health-code violations.

"'André, you'll say, you're a complete bastard," said Arthur, who broadcasts on the small upstart BLVD 102.1. "And I'll say, tsk, tsk, that's reality."

But the climate for greater self-reflection that has emerged since the attack has prompted at least one poubelle star to break ranks.

Sylvain Bouchard, a morning host on FM 93, offered an on-air apology earlier this week.

"I recognize it; I erred," he said. "It won't happen again."

Despite often discussing Islam on his show, Bouchard admitted to his listeners that his researchers didn't have the name of a single Muslim community leader among their contacts.