"Many of you have houses, families, you have payments each month on your mortgages," Couillard said at an event in Brossard in defence of the Liberals' new budget.
"Well, this is the situation Quebec is in: We now have annual payments of $11 billion on our debt. That's more than we put into our elementary and high schools," Couillard said.
"Every day, it's $30 million — $30 million yesterday, $30 million today and $30 million tomorrow — before a single dollar can go into our schools and hospitals. That is the situation we are facing," he continued.
The Liberal government unveiled its ambitious new budget earlier this week.
The government's zero-deficit mission is reflected in its $100-million budget for 2015-2016, with cuts and massive restructuring in health care, education and other costly departments.
Couillard on Sunday said Quebec needs to shake off its bad habit of passing deficit budgets.
He said only eight of the past 30 budgets were in the black.
"We could have chosen just to ignore reality, ignore the problem. Sweep it under the rug as usual and say, 'They will take care of it.' Who's 'they?' It's us, citizens, Quebecers and the next generation," he said.