In 2010, Labor got 50.12 per cent of the national two-party preferred vote and fell short of an outright majority. In 2016, the Coalition won 50.36 per cent and retained government by a single seat. The 2019 result will be similar - on the latest figures the Coalition is set to get a little over 51 per cent two-party preferred.

Complex political cross-currents have made it difficult for either major party to carve out a decisive lead and long-held electoral norms are shifting.

There were swings against the Liberals in a clutch of inner-urban seats once considered blue ribbon, but they did well in outer-metropolitan electorates.

In Warringah, in Sydney's north, the seat with the highest median household income in the country, former prime minister Tony Abbott lost with a swing of almost 19 per cent, more than enough to install independent Zali Steggall as the new member.

But just 70 kilometres west of Warringah, in the electorate of Lindsay, which takes in Penrith, the Liberals won with a chunky 6 per cent swing. There was also a solid swing to the Liberals in the adjacent Labor seat of Macquarie, which hung in the balance on Sunday night.

When former Liberal prime minister John Howard won Lindsay in 1996, it contributed to a new voter category being coined: the Howard battlers. Like America's "Regan Democrats", Howard's battlers have always been a tricky group to define and much has changed in the 23 years since that Liberal triumph.

But many in the Howard battler heartland have now become Scott Morrison's battlers.

The Liberals also gained ground in some of Labor's western Sydney strongholds, although not enough to win. In McMahon, held by shadow treasurer Chris Bowen, there was a 5 per cent swing against the ALP, while in Chifley, held by frontbencher Ed Husic, the swing away from Labor was 6.3 per cent.

One of the few bright spots for Labor came outside Sydney - it picked up the seat of Gilmore on the NSW south coast.

There was a comparable trend in Melbourne. The Coalition held onto Higgins, a Liberal bastion once occupied by former treasurer Peter Costello, but suffered a 6.4 per cent swing.

But in the outer-urban seat of La Trobe, which betting markets predicted would fall to Labor, there was a swing in favour of the Liberals.

In Chisholm, another suburban seat tipped to go to Labor, the Liberals were ahead on Sunday night, although the result was still too close to call.

The outer-urban electorates of Casey, Deakin and Flinders were all comfortably held by the Liberals, foiling Labor hopes of significant gains in Victoria.

But the Coalition's strong showing in outer suburbs was also evident in Brisbane, where it held three seats with a margin of less than 2 per cent.

There were big swings to the Liberal National Party in the ultra-marginal seats of Forde (7 per cent) and Petrie (5 per cent) while Home Affairs Minister Peter Dutton gained ground in his seat of Dickson, on Brisbane's northern outskirts, defying widespread expectations of defeat.

The LNP also defeated Labor's Susan Lamb in the neighbouring electorate of Longman, with a swing of almost 4 per cent.

Labor is also fighting to retain Lilley, the Brisbane suburban seat once held by former Labor treasurer Wayne Swan, after a 5 per cent swing to the LNP. It remains too close to call.

The Coalition performed especially well in a string of Queensland coastal electorates, where the future of the proposed Adani coal mine and unemployment were major issues.

The party easily won the Townsville-based seat of Herbert, which it lost to Labor's Cathy O'Toole at the last election by 37 votes.

Two marginal seats south of Townsville - Capricornia and Dawson - saw swings of around 11 per cent to the government.

Opinion polls suggesting the two-party preferred vote in Queensland would be around 50:50 proved fanciful - the LNP in fact polled 57 per cent to Labor's 43 per cent. The Coalition now holds 22 of the state's 30 electorates (and possibly 23 if it wins Lilley).

A swag of LNP electorates have also shifted into the safe-seat category at this election, making it more difficult for Labor to make headway in the state next time.

The Coalition's path to re-election relied on a strong showing in Tasmania and it delivered. The Liberals took the seat of Braddon in the north-west of the state with a swing of nearly 5 per cent and was ahead in the volatile electorate of Bass on Sunday night, although the result was still too close to call. The voters of Bass have now elected a new member from a different party at each of the past four elections.

Speculation that ALP could pick up seats in Western Australia and that the state might be decisive in the overall election result was unfounded.

The ALP was eyeing four seats in WA - Swan, Hasluck, Stirling and Pearce. But as in other big cities, the outer suburbs remained strong for the Liberals.

Labor's Anne Ally was on Sunday night ahead in the marginal seat of Cowan, but the seat was still too close to call. It was the same story in the Adelaide seat of Boothby, where the Liberal incumbent, Nicolle Flint, was marginally ahead of Labor's Nadia Clancy.