MONTREAL -- The key to a Parti Quebecois majority government could lie in 10 per cent of Quebec's ridings where the party lost electoral nail-biters just 18 months ago.

An analysis by The Canadian Press reveals that Premier Pauline Marois's minority PQ fell short in 13 of the province's 125 electoral districts by fewer than five percentage points in September 2012.

These near-miss ridings are scattered across southern Quebec, with six concentrated on the edges of Montreal and one within city limits. Among the others, one is found in the western Quebec area of Outaouais and another near Quebec City, while the province's southeastern corner and its central Mauricie region each have two.

Demographically, all but two of the ridings share a common feature: they are home to big francophone communities. Eleven of them have francophone populations larger than the provincewide average of 84 per cent.

The first days of the campaign, which will send Quebecers to the polls April 7, highlighted the degree to which the PQ offensive will play out on a very limited section of the chessboard.

The party needs to win nine more seats than the 54 it captured in 2012 to deliver Marois a majority government, which means even an uptick in PQ support in some of these areas could be the difference maker.

Recent polls have suggested the PQ's popularity has climbed to within striking distance of a majority, while the rival Liberals and Coalition, who hold these potential swing districts, have lost ground.

Shortly after Wednesday's election call, Marois's campaign made a beeline toward the Mauricie, roughly halfway between Montreal and Quebec City. In 2012, the official Opposition Liberals narrowly won the local ridings of Maskinonge and Trois-Rivieres.

On Day 2, she held an event in the crucial Montreal district of Verdun, where the PQ has named star candidate Lorraine Pintal, director of one of the city's most prestigious theatres.

Then on Friday, Marois's campaign rolled into the critical outer suburbs north of Montreal, known as la couronne nord, where she named another star contestant in the Groulx riding: former student protest leader Martine Desjardins.

In 2012, the PQ was beaten out in most of the closely fought Montreal-area ridings by the third-place Coalition party.

The PQ has also lined up notable hopefuls in other tight ridings, including former journalist Alexis Deschenes in Trois-Rivieres and ex-Bloc Quebecois MP Pierre Paquette, who will try to beat Coalition leader Francois Legault in L'Assomption, north of Montreal.

To win all of these key districts, the PQ will have to beat eight Liberal and five Coalition incumbents.

The PQ has made efforts since the last election to woo supporters from its adversaries with the help of its controversial secularism charter. The proposal calls for a ban on public employees from wearing conspicuous religious symbols at work.

Polls have suggested the charter, which has drawn criticism from PQ opponents, is popular among voters in the province's outlying areas.

The PQ could also enjoy an added advantage this spring in two of these 13 enticing districts.

The Liberal-held riding of Megantic, the scene of last summer's devastating train derailment, could be in play thanks to local praise for Marois following her quick response to the disaster.

Meanwhile, in the Saint-Jerome riding north of Montreal, the Coalition's star incumbent, Jacques Duchesneau, well-known as an anti-corruption crusader, declined to seek re-election.

Before she launched the campaign, Marois also tried to till the ground in potentially pivotal areas such as the Mauricie.

She announced 85 pre-election investments there last month worth millions of dollars. Opponents mocked her for travelling the region in a helicopter during the spending spree, prompting Coalition MNA Christian Dube to say she was playing "Santa Claus."

One of Marois' main competitors, Liberal Leader Philippe Couillard, also made an early campaign stop Thursday in the Mauricie battleground. Liberal incumbent Jean-Paul Diamond is trying to hang onto Maskinonge, which he won in a tight three-way race in 2012.

But as the PQ advances on these 13 tantalizing electoral targets, it will also be looking over its shoulder.

The party's potential gains could be offset in eight ridings where it won 2012 squeakers by fewer than five percentage points. The party edged the Coalition in seven of those districts and beat the Liberals in the other one.