As the South Australian election campaign enters its final fortnight, a complacent betting market continues to rate the Liberals a $3.60 long shot. That should change following today’s Newspoll: it shows a dead heat on two-party preferred, with the Liberals leading on the primary vote 39% (up 4% on the previous October-December poll) to 36% (down 1%).

Equally alarmingly for Labor, Mike Rann’s disapproval rating (up 10% to 48%) has surged past his approval (down 5% to 45%). This is remarkably similar to what happened to Alan Carpenter in 2008, when his net rating went from 9% positive at the start of the campaign to 6% negative at the end.

However, there is perhaps some consolation for Labor in that the period covered by the poll extends all the way back to January. The poll that recorded Carpenter’s collapse was conducted in the final week of the campaign, and captured the backlash from his opportunistic decision to go to the polls six months early. Furthermore, while the Western Australian ALP’s campaign was blighted by a panicky response to its declining public standing, their South Australian counterparts have had the better of the past fortnight.

Shortly before the formal campaign period began, the government outmanoeuvred the Opposition over the duplication of the Southern Expressway, an artery that currently flows in one direction towards the city in the morning and in the other direction away from it in the afternoon.

On the very day the Liberals were to make their own announcement, based on a $280 million costing the government had floated earlier, Labor got in first with a more detailed new plan with a price tag of $370 million. The rug having been pulled from under them, the Liberals sent out shadow finance minister Rob Lucas to “take one for the team” (in the words of a Liberal source quoted by Greg Kelton of The Advertiser) by announcing that while Labor’s promise would be matched, the details would now have to wait until later.

The Liberals have also hit static over the future of the Royal Adelaide Hospital, where they are proposing a $700,000 expansion in place of a $1.7 billion Labor plan to replace it with an entirely new facility. It emerged the Liberal plan had been drawn up by an architect with no experience in designing hospitals, and that the $700 million estimate had come from a consulting firm that considered it merely a “ballpark” figure.

Even so, media reports have indicated both parties’ tracking polls point to swings of up to 7% in the key marginal seats, a figure perfectly consistent with the Newspoll result. A uniform swing of that size would see seven seats shift from Labor to Liberal, which net of other changes would leave both on 21 seats, with four independents and Nationals MP Karlene Maywald in the middle. Four of these seats — Norwood, Newland, Hartley and Morialta — are located in a cluster in the eastern suburbs, where Labor sources say their sitting members are encountering a particularly hostile environment.

A potential saving grace for Labor is that the Liberals have nominated contentious former federal MP Trish Draper in Newland, where voters are receiving regular reminders of her considerable personal baggage in their letterboxes.

Labor observers believe they are travelling better on Adelaide’s periphery. Aided in no small part by the Southern Expressway issue, they are thought to remain at least competitive in the outer southern seat of Mawson, despite its slender 2.7% margin. At the opposite end of town, rapid urbanisation is improving Labor’s position in the Gawler-based seat of Light, although a margin of just 2.4% means the odds remain stacked against sitting member Tony Piccolo. Labor has more reason to be optimistic about the southern coastal suburbs seat of Bright, where the popularity of incumbent Chloe Fox is such that her 6.9% margin should be enough.

If five of the aforementioned seven seats should fall without corresponding gains, Labor will find itself teetering without a parliamentary majority. However, Labor is bullish about its prospects of recovering the southern suburbs seat of Mitchell from ex-Labor independent Kris Hanna. This is partly because Hanna won’t enjoy the spillover effects from ally Nick Xenophon’s staggering upper house vote in 2006, but also because the Liberal resurgence will make it harder for him to stay ahead of them at the second last count. The Liberals would have done well to have played dead in the electorate, but the local party branches have had other ideas, fielding an attractive candidate and making a determined effort on her behalf.

On the other side of the equation, the Liberals are a strong chance of recovering two seats currently in independent hands, and also of unseating Karlene Maywald in Chaffey. Strongly conservative Mount Gambier is being vacated by long-serving sitting member Rory McEwen, and despite the efforts of Grant district mayor and independent candidate Don Pegler, most observers expect Mount Gambier mayor Steve Perryman to recover the seat for the Liberals. The Liberals are also unquestionably travelling better now than they were when they lost the Frome by-election to Geoff Brock a year ago, and are hoping that result will prove to have been an aberration.

The one cross-bencher who is sitting pretty is Bob Such, who holds the southern Adelaide seat of Fisher. Such effortlessly retained his seat at two elections after parting company with the Liberal Party in 2002, and nobody expects different this time. If there’s any substance to today’s Newspoll result, a lot could depend on his attitude to his former Liberal colleagues over the coming weeks.