Projet Montréal is saying that a giant plastic dog doo, meant to remind owners to clean up after their pets, has gone too far.

The oversized excrement, complete with circling flies, sits atop a bus shelter at the southern edge of Dorchester Square downtown.

It's part of a $700,000 cleanliness campaign by the City that includes videos, billboards, and street performances. The message: your waste has a bigger impact than you think.

"Every year we do the same campaign with traditional communications," said Anie Samson, member of the city's executive committee. "This year we decided to go further and make it more punchy."

If it strikes some people as going too far, that's the point, Samson said.

"It's a way to sensitize people: this is what happens when you litter. We need people to react and make city cleaner," she said.

The city's campaign, which also includes a pile of fake dog poo baggies, has been a hit on social media. (CBC)

Craig Sauvé, a city councillor for the Southwest borough with the opposition Projet Montréal, says the ad is in bad taste.

"I feel this misses the mark. They want to shock and they did shock," he said. " How will this appear to tourists, why is it in front of a historic park we just renovated?"

Samson said the city will assess whether the campaign worked later in the fall.