Both sides need to win majority in NSW

If Malcolm Turnbull is to have any hope of keeping his prime minister-status, the Liberal Party must maintain its hold on a swag of marginal seats across NSW.

Labor has never won a federal election without also winning a majority of seats in the state, while the last time the coalition won without a majority in NSW was in 1961.

NSW is usually viewed as a Labor state but the ALP's stocks began dwindling when Julia Gillard overthrew Kevin Rudd in 2010.

In the 2013 election, it was feared western Sydney - home to six marginal seats - would be the danger region for the Labor party.

But the predicted blowout never eventuated and voters turned towards the coalition by just 2.99 points.

Historically, the big vote-swingers for NSW are jobs creation and the cost of living.

Education and health are also consistently named in polls as the areas of most concern while funding for big-ticket transport projects such as the controversial 33km WestConnex motorway in Sydney also hold weight.

Mr Abbott's "Stop the Boats" campaign strategy sealed the coalition's success with lower-income voters and new migrant communities in the critical western Sydney battleground last election.

But with Labor shifting its policy to embrace offshore processing since then, it's unlikely the issue will come into play at this year's poll.

Meanwhile, the Greens have used their point of difference to target left-wing voters in the inner-city electorates of Grayndler and Sydney. Those strategies, however, are yet to help them secure those long-held Labor seats.

NSW has 47 seats - contributing a third of all lower house MPs - with at least 17 electorates believed to be in play.

A recent Galaxy poll showed the Liberal Party is making a comeback in marginal NSW seats, especially in the critical western Sydney region, following a concerted campaign from the prime minister.

If those patterns play out this Saturday, it's likely Mr Turnbull will get to keep his keys to the Lodge.