Queensland is regarded as a key battleground for the 2016 federal election with five marginal Coalition seats that Labor needs to win if it hopes to take office.
Prime Minister Malcolm Turnbull focused on sandbagging inner-city issues in key Coalition seats on the first day of the campaign, while opposition leader Bill Shorten was in the far north hoping to regain a foothold for Labor.
After Labor was heavily defeated at the last federal election, there is expected to be some swing away from the Coalition in the Sunshine State.
Of the 30 federal seats in Queensland, Labor holds just six and less than 20,000 votes could decide if it doubles that number to get a chance of forming government.
Petrie is Australia's most marginal seat, held by the L-N-P by just half a per cent.
Labor will also be targeting Capricornia, Bonner, Brisbane, Forde and Leichhardt.
The Coalition has designs on Lilley and Moreton and is certain to take retiring one-term M-P Clive Palmer's seat of Fairfax.
Griffith University professor of politics Anne Tiernan says if the seat of Brisbane falls, Labor may be on the way to taking office.
