MONTREAL -- Quebec's four main political parties offered voters distinct visions on the first day of the election campaign Thursday as leaders began criss-crossing the province in their drive to emerge victorious Oct. 1.

The incumbent Liberals said they guarantee stability and warned Quebecers against choosing another party when they head to the polls.

Doing so would compromise four years of sacrifice and hard work that helped bring about the strong economic growth the province is enjoying, said Liberal Leader Philippe Couillard.

He boasted of the "perfect" AAA rating a Chinese credit agency recently gave Quebec, representing the first time the province has received such a score in decades.

"If you read the comments in that report, the agency said the growth is largely due to budgetary decisions of the government," he said.

But Couillard's opponents were eager to attack decisions that reduced the budgets of the health and education departments in the early years of the Liberal mandate.

Francois Legault, leader of the Coalition Avenir Quebec, the party that has led the polls for months, started his first official campaign speech targeting Couillard's cuts.

"I will never forgive (Couillard) for taking the worst decision to cut in services for kids with learning difficulties," Legault said. "It's inexcusable. Do Quebecers want to keep in power a man who is willing to sacrifice the future our of kids?"

Despite labour shortages and record-low unemployment across the province, as well as budget surpluses and rising salaries, Legault said Quebec "can do better."

The Coalition is offering Quebecers a nationalist government that would demand more powers from Ottawa on issues such as immigration and language.

Legault's party is also offering voters a federalist alternative to the Liberals and a nationalist alternative to the Parti Quebecois.

He said he wants to reinvest in education and in other services as well as cut taxes for Quebecers, positions his opponents say are not financially feasible.

PQ Leader Jean-Francois Lisee, whose party is trailing a distant third in the same polls that have the Coalition in first, also took aim at the Couillard government's budget decisions.

"They created human misery and that was documented every year," Lisee said in his opening speech.

The PQ is offering Quebecers a strong central government that "takes care of its citizens."

Taxes will remain where they are, Lisee said, in order to fund more social services, including subsidized lunches for elementary students across Quebec.

"We have to turn the page on 15 years of Liberal reign," said Lisee, seemingly forgetting the 19 months his party was in power from 2012 to 2014.

"The Liberals act as though there have been no cuts. Nobody believes them. The Caquistes (the Coalition) act as though they can cut taxes without cutting services. Nobody should believe them. If you hated Liberal austerity, you are going to hate Caquiste austerity."

Later on Thursday, it was Quebec solidaire's turn at the mic on Day 1.

With only three seats in the legislature, the party is hoping to steal some ridings from the PQ on the island of Montreal as well as make a breakthrough in other parts of the province.

The left-wing sovereigntist party is promising subsidized dental care for all, 50 per cent off public transit fares and fully subsidized education from elementary school to university.

"After 40 years of alternating between the old parties, Quebecers are ready for something new, and new is here," said Manon Masse, one of two "spokespeople" for the party, which does not have any "leaders."

The 39-day campaign is the longest possible under Quebec electoral law and Liberal strategists have said privately it means more time to put the Coalition under the microscope.

Couillard has said the extra days were necessary because of the Labour Day weekend and the time needed to prepare for three debates.

"We'll have more time to speak to Quebecers," he reiterated Thursday.

At dissolution, the Liberals held 68 seats, the PQ 28, the Coalition 21 and Quebec solidaire three.

There were also five Independents in the 125-seat national assembly.