Opposition leaders, especially those trying to manage expectations in the face of an anticipated victory, are often heard to compare the task facing them to climbing Mount Everest. These words were repeated ad nauseum by Kevin Rudd in 2007 when polling consistently showed him headed for a historic landslide (which, lest we forget, did not entirely eventuate), and they were given another airing yesterday by Opposition Leader Tony Abbott.

If the analogy has any meaning, it is in relation to the added difficulty a party faces when its path to victory involves dislodging the other side’s sitting members.

While it can normally be taken for granted that this will apply to the opposition rather than the government, in the present situation the roles are largely reversed.

Leaving aside technicalities involving the status of the Western Australian Nationals, the Coalition goes into the election with 73 seats out of 150, and it has been all but gifted a further two with the retirement of independents Tony Windsor and Rob Oakeshott, whose regional New South Wales seats of New England and Lyne look certain to revert to Nationals-voting type.

Labor, on the other hand, has a starting point of only 71 seats, after winning 72 at the last election and losing the central coast NSW seat of Dobell to the misadventures of Craig Thomson (although those who assume a Liberal win there to be a foregone conclusion should consider the precedent of neighbouring Robertson in 2010, when Labor actually picked up a swing despite the disastrous one-term tenure of its former member Belinda Neal).

Labor thus faces the daunting challenge of stitching together a net gain of at least three seats in an extremely challenging political environment.

By far the most promising terrain for potential gains is Queensland, where Labor decisively gained nine seats under Rudd in 2007 only to lose seven under Julia Gillard in 2010. But while Labor might hope the return of the home-state hero will furnish it with gains to compensate for likely losses elsewhere, it cannot be entirely confident that any swing will be translated into seats at the expense of the Liberal National Party’s class of 2010.

A case in point is the electorate of Longman, located on the cusp of outer-northern Brisbane and the Sunshine Coast and requiring a swing of 1.9%. Despite evidently strong anti-Labor sentiment at the time of the 2010 election, voters might well have harboured doubts about the candidate offered up by the LNP — Wyatt Roy, a university student who had turned 20 just three months earlier. Roy nonetheless emerged victorious over one-term Labor member Jon Sullivan and has since accumulated three years of parliamentary experience, in which time he has notably failed to embarrass himself.

While most voters will no doubt have other things on their minds, some of the kind-hearted Longmanites might baulk at the thought of cutting short a young man’s promising career in his dream job.

Overall, Queensland is home to seven LNP seats on margins of less than 4%, each of which has a first-term sitting member who has spent the past three years building up his or her personal vote.

These seats are spread evenly throughout the state, encompassing inner Brisbane (Brisbane, with a margin of 1.1%, and Bonner on 2.8%), outer Brisbane (Forde in the south and aforementioned Longman in the north, respectively on 2.8% and 1.6%) and the regions (Townsville-based Herbert on 2.2%, the Whitsunday region seat of Dawson on 2.4%, and Flynn, covering Gladstone and its surrounds, on 3.6%).

Against the prospect of an improved performance in Queensland must be weighed the likelihood of losses in states where Labor performed well last time, notably Tasmania and Victoria.

“Rudd’s return appears to have transformed Labor’s previously disastrous position in NSW, but support is believed to remain soft in the much-touted battlegrounds of western Sydney …”

The Liberals have only won seats in Tasmania at one election since 1996, that being when a backlash against Mark Latham’s forestry policy contributed to the loss of the northern regional seats of Bass and Braddon in 2004. That looks very likely to be repeated this time around, with the unpopularity of the Labor-Greens government at state level providing considerable weight in federal Labor’s saddlebags.

Labor also has to fight to defend its other two Tasmanian seats of Lyons and Franklin, and does not appear to have much chance of unseating independent Andrew Wilkie in the Hobart seat of Denison.

The Liberals also look set to improve on poor performances in Victoria and South Australia last time around, though neither state offers a target-rich environment in terms of marginal seats.

In Victoria, Labor looks unlikely to repeat its historically exceptional performance in winning the outer Geelong and Great Ocean Road electorate of Corangamite, which it won for the first time in 2007 and retained narrowly in 2010. In Melbourne, a swing of any substance will cost Labor the eastern suburbs seats of Deakin and La Trobe. Beyond that, Labor’s next most marginal seat in Victoria is Chisholm, located a long way up the pendulum with a margin of 5.8%.

Successive strong performances for Labor in Adelaide have left it no seats there with margins of less than 6%, although the party is concerned about the inner-western suburbs seat of Hindmarsh, which Steve Georganas holds on a margin of 6.1%.

Rudd’s return appears to have transformed Labor’s previously disastrous position in NSW, but support is believed to remain soft in the much-touted battlegrounds of western Sydney, with bookmakers favouring the Liberals to gain Lindsay, Greenway and Reid.

The two Northern Territory seats could hold surprises if the results of last year’s Territory election are anything to go by. Labor was blindsided by huge swings in remote Aboriginal communities while retaining most of its ground in the normally decisive suburbs of Darwin, whose large public service population may have been spooked by Campbell Newman’s job cuts in Queensland. The respective trends could make life interesting for both Natasha Griggs, who gained Solomon for the Country Liberals in 2010, and Labor veteran Warren Snowdon in Lingiari, who has little left of his margin after suffering a big swing last time.

If Labor is still in the hunt on election night as the picture becomes clearer in the eastern states, there will be a nervous wait for results from Western Australia. Labor holds only three of the state’s 15 seats; talk of them doing even worse this time has largely receded with the return of Rudd.

Instead, two Liberal-held seats look to be in Labor’s firing line: the eastern suburbs seat of Hasluck, which Ken Wyatt gained from Labor in 2010, and the perennially tight inner-suburban marginal of Swan.

The 2.2% swing required in the southern Perth fringe seat of Canning might look achievable on paper, but the current narrowness of the margin is down to the candidacy in 2010 of popular former state ALP government minister Alannah MacTiernan, who outperformed the state swing by about 5%. This time MacTiernan has a seemingly secure path to Parliament as the successor to Stephen Smith in the seat of Perth.

The only vulnerable WA seat for Labor looks to be the coastal southern suburbs seat of Brand, where Gary Gray succeeded Kim Beazley in 2007 and currently sits on a margin of 3.3%.