Many elections are fought out mainly in a particular geographical area – marginal seats are often concentrated, for example, in a readily definable mortgage belt. But this New South Wales election is not like that; the seats of interest are spread pretty evenly across the state.

The one exception is in Sydney’s middle southern and south-western suburbs, where there is a solid block of 19 safe Labor seats. Only on the periphery of this region do things get more interesting.

Three seats make up the inner-city zone where Labor’s main rivals are to its left. In Balmain, formerly called Port Jackson, Labor MP Sandra Nori won last time with a margin of 7.1% against the Greens, but her retirement this year means the Greens will make a contest of it, although Labor is still favoured to hold on.

The other two are unlikely to see an upset. Labor’s Carmel Tebbutt won Marrickville at a 2005 by-election with a margin of 5.1% against the Greens, but with the Liberals not directing preferences she should be safe this time. And independent Clover Moore in Sydney (formerly Bligh) is even safer, with a margin of 15.0% against Labor.

In the far south of Sydney, beyond the Georges River, is another clump of marginals. The adjacent seats of Menai (8.9%) and Miranda (9.1%) are emblematic of Labor’s strong performance in 2003; having first won them in 1999, they secured further big swings to build up a substantial buffer. Both are regarded as “must-win” seats for the opposition.

However, in light of the Liberals’ poor performance in the campaign, commentators are now saying – in contrast to the conventional wisdom a few weeks ago – that Labor’s margin will be too big to overcome this time. That’s certainly the case in spades for neighbouring Heathcote (12.3%), which extends down into the northern suburbs of Wollongong.

On the far south-western fringe is Camden (8.7%), the ALP’s only gain from the Liberals in 2003. The redistribution has substantially improved it for Labor, but the Liberals are running a strong campaign with local mayor Chris Patterson. Like Menai, it is one of the five marginal seats on which a poll in this morning’s Daily Telegraph bases its conclusion that Labor has a two-party-preferred lead of 58% to 42%.

Next door is the new seat of Wollondilly, created to replace the abolished rural seat of Lachlan, and containing mostly the more rural parts of the old Camden and the northern end of the old Southern Highlands (now Goulburn), plus bits of urban Campbelltown. It is notionally Labor, with a 4.6% margin, making it the government’s third most marginal seat and an obvious Liberal target.

Nonetheless, as with virtually all the Labor marginals, the Liberals now seem pessimistic, and it’s likely that Labor’s Phil Costa – a last-minute recruit who had previously signalled an intention to run as an independent – will become the member for Wollondilly.