Queensland is regarded as a strategic battleground for the 2016 federal election with five marginal Coalition seats that Labor needs to win if it hopes to take office.
Brisbane was in focus on the first day of the formal election campaign, after Liberal-National Party MP Teresa Gambaro's decision to retire and not contest the July vote.
The battle for Queensland's capital is also one of firsts, as the federal election will be the first time two openly-gay major party candidates are standing for the same seat.
One of them is the LNP's Trevor Evans.
But Mr Evans says he won't use sexual orientation to define his campaign.
"It's unfortunate that there are other candidates out there starting their press releases describing themselves as openly gay or whatever else. It's not about putting people into boxes, it's about looking at what they have to contribute. I'm a hard worker, I'm going to be focusing on the issues that matter and I'm going to be focusing really hard on selling the very positive message that the Malcolm Turnbull government has for the future."
His Labor rival, Pat O'Neill, says he will be campaigning hard for marriage equality.
I don't think it's an issue that there are two openly-gay candidates standing, I think the issue is that we have a parliament so out of touch with the general population. You know, we could be standing for parliament, but we are not treated equally under the law. So it's not reflective of the candidates sitting, it's reflective of where society is and how out of touch the LNP government is."
Visiting electorates at opposite ends of Queensland, Prime Minister Malcolm Turnbull focused on sandbagging inner-city issues in key Coalition seats, 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 LNP 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 MP 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.
"I think the campaign will be around the south-east and a lot of that will be around the transition to the new economy and the cities and housing agenda, housing affordability such an issue in Queensland and jobs and growth."
Professor Tiernan says last month's local elections could be an indicator of how the votes will fall at the federal election.
"I think the recent Brisbane City Council and the council elections more generally are a better bellwether (leading/indicating a trend) of what's going on in Queensland at the moment. So the LNP did pretty well in those when you think about it, Labor didn't do so well - they really came under challenge from the Greens. So I think the Greens and Independents are the real unknown in the Queensland campaign this time. In regional areas, the Independents, and then in you know metropolitan inner areas the Greens."
In the Senate, eyes are on the Greens.
The party's first Queensland senator, Larissa Waters, says she hopes to be joined by candidate Andrew Bartlett on an issue that the Greens believe appeals to city and coastal electorates.
"Here in Queensland, we Greens have been listening to the community and we've heard that that's what they want: action on clean energy, protecting the reef, dealing with inequality. And we're looking forward at this election to really increasing our numbers."
