The members of the Union of Quebec Municipalities (UMQ) responded to comments made by Moreau on Wednesday in which he said the mayors of Laval and Longueuil were taking their citizens for "morons."
The comments were made after those two municipalities raised property taxes by 3.2 and 3.9 per cent respectively in response to the Quebec government's $300-million cut to transfers to municipalities.
Moreau's interference in how municipalities run themselves is "unprecedented," said UMQ president Suzanne Roy.
Victoriaville mayor Alain Reyes said Moreau is attacking the legitimacy of local leadership.
He said Moreau's tactics were "infantilizing" and an affront to democracy.
Moreau issues ultimatum
On Wednesday, Moreau threatened municipalities to back down on their tax hikes or receive less money from the province.
“I don’t want mayors in Quebec to do politics, justifying their tax increase on the back of the government,” Moreau said.
Laval has a surplus of $111 million while Longueuil’s is $10.7 million.
Moreau ordered Longueuil Mayor Caroline St-Hilaire and Laval Mayor Marc Demers to re-think the 2015 tax increase.
"If they don't do that, we'll reduce the transfer between the government of Quebec and the municipalities of Laval and Longueuil, to an equal amount and we'll reimburse the taxpayer."
Moreau 'flirting with abuse of power'
St-Hilaire said Moreau was treading dangerously close to abusing his power as municipal affairs minister.
"Quebec thinks we are ATMs," she said at the news conference late Thursday morning, adding that every time the provincial government has a deficit it stick its hands in municipalities' pockets.
She said the surplus Longueuil currently has belongs to the residents of Longueuil, not the provincial government.
Demers of Laval said the surplus in Laval is already earmarked for projects to overhaul infrastructure in the city that he said was neglected during Gilles Vaillancourt's two-plus decades as mayor.
Demers pointed to the fact that the city's sewers empty into the river every time it rains too much.
"We have a city to rebuild, and everyone knows it except the municipal affairs minister," Demers said.