Held by Labor on a margin of 4.2 per cent, all eyes will be on the NSW seat of Eden Monaro as a key indicator for the outcome of this year's election.
Eden Monaro holds a special significance in the election landscape because, since 1972, whatever way the electorate swings, the government follows.
As a result, both the Labor and Liberal parties are running seasoned candidates in the seat.
Created in 1900 Eden Monaro remains one of the original 75 seats contested at the first Federal Election in 1901.
Before the Second World War, Eden Monaro was largely considered a safe conservative seat, becoming marginal thereafter. The Labor Party's Bob Whan held the seat from 1972 to 1975, which is seen as the beginning of the seat's bellweather status.
Eden Monaro sits in the far south-east corner of New South Wales, taking in the south coast, the southern and eastern areas around the ACT and the Snowy Mountains.
Main towns include Batemans Bay, Bega, Cooma, Eden, Jindabyne, Queanbeyan, Merimbula, Moruya and Sutton.
The seat takes its name from the town of Eden and the Monaro district of southern NSW.
It's home to prize grazing land, with the rural landscape supporting beef, sheep, wool and dairy farming. It's also the home of the Snowy Mountains hydroelectric scheme as well as Australia's snowfields, making tourism an important industry.
The seat is held by Labor MP and Minister for Defence Material Mike Kelly, pictured right, who is standing for his third term.
At the last election Mr Kelly reversed Labor's national trend, boosting his margin to 4.2%.
The former colonel with the Australian army also served as a military lawyer with the Coalition Provisional Authority in Iraq from 2003-2004. In that time he was repsonsible for highlighting the use of torture on Iraqis at Abu Ghraib.
Mr Kelly has also been handpicked by the current Prime Minister Kevin Rudd to take on the Defence portfolio should Labor win at the 2013 election.
Two of his main policy passions are renewable energy and the NBN.
Taking on the Labor MP is the Liberals candidate Peter Hendy, pictured left. A business and politics stalwart, Mr Hendy has spent time as a Howard-era government advisor to the then Industrial Relations Minister, Peter Reith.
Mr Hendy is a key Liberal attack dog, largely campaigning around the rising cost of living pressures, the effects of the carbon tax and border control. He has put small business at the heart of his 2013 campaign.
Other candidates whose preferences will prove crucial in deciding the two-party preferred vote....
The Greens: Catherine Moore
The Palmer United Party: Dean Lynch
The Stable Population Party: Martin Tye
Median age: 43
Average children per family: 1.9
Median weekly household income: $1,022
The town of Queanbeyan is the hub for most of the electorate's economic and development activity, with new home buyers moving into the area from nearby Canberra.
The largest proportion of the Eden Monaro population was born in Australia (80%), followed by the United Kingdom (5%) and New Zealand (1%).
The overwhelming majority of voters speak English at home (89%).
IN DEPTH: QUEANBEYAN
Most Queanbeyan voters live alone (41%) which is almost double the national average (24%) and own their house with a mortgage (30%).
Incomes in the area are on par with the average Australian, the most households (14.6%) earning $78,000-$103,999 annually.
Similar to the general population, just under 40% of families from Queanbeyan are couples with no children (37.8% for Australia).