If the Turnbull Government is to make ignominious history and fall at this year's election, then the magic number for Labor is a turnover of 21 seats.

That would require a uniform swing of 4.3 per cent and will be very hard to do, no matter when the election is called.

But in the post-Howard era of politics, nothing is now impossible.

So, with the phoney campaign afoot as the nation waits for an official election date, the ABC contacted party hardheads from Labor and the Coalition to get their take on where the battlelines will be drawn.

Labor concedes it is coming from a long way behind, but has been buoyed by its start to the year.

Labor has taken risks and run hard. That has paid off, and it intends to keep the pace up until polling day.

Coalition strategists believe Malcolm Turnbull will win, but concede he has lost his lustre since Christmas.

They once hoped the Government would win seats at the poll, now they are counting a growing list of seats they will have to defend. Right now they believe that there are 10 in the firing line.

Both sides broadly agree on the battle zone and, as usual, ground zero is in Queensland and NSW.

All the numbers below are based on Antony Green's post-redistribution pendulum.

Queensland

Labor has its eyes on the Central Queensland seat of Capricornia, (LNP 0.8 per cent) which stretches along the coast from Rockhampton to Yeppoon, and hopes to pick up the neighbouring seat of Dawson (LNP 7.6), although it admits that will be much tougher.

Heading north it will target Herbert (LNP 6.2), based around Townsville, and Leichhardt (LNP 5.7), which stretches from Cairns across all of Cape York.

Heading south, Labor will turn its sights on Longman (LNP 6.9) and Dickson (LNP 6.7).

In the capital Labor has high hopes for the seat of Brisbane (LNP 4.3) and also Petrie (0.5)

To the south of the city Labor is eyeing Forde (LNP 4.4).

The Coalition is worried about Brisbane and the job has become harder with sitting MP Teresa Gambaro retiring.

It expects to pick up Fairfax from Clive Palmer.

It also holds fears for Petrie, but believes it will hold Capricornia, and is unwilling to concede any other seats are threatened at this stage.

But both sides have a mantra in common, "if the swing is on in Queensland, it's on".

Should that happen, then Labor will be in with a chance of pulling off an unlikely victory.

NSW

Labor has preselected former NSW deputy opposition leader Linda Burney for the Sydney seat of Barton, which is now notionally an ALP seat (5.4). Labor believes she will win it.

After that Labor admits the hunt becomes tougher, but the next three would be Macarthur (Lib 2.8), Lindsay (Lib 3.0) and Reid (Lib 4.4).

Outside Sydney, from the south coast to the summit of Australia, the seat of Eden-Monaro (Lib 2.6) is in play.

Also Dobell is also in play on the central coast. The seat was made notionally Labor (ALP 0.3) by the redistribution.

The Coalition is expecting to lose Barton and is worried about Eden-Monaro.

The redistribution has made Dobell tricky, as there would have to be a swing to the Government to hold it.

The Greens also have some hopes of taking seats from Labor in NSW, and will target the inner city seats of Grayndler and Sydney and the Far North Coast seat of Richmond.

Victoria

In the early surge of enthusiasm for Mr Turnbull, Labor feared it would lose ground in Victoria. It is more optimistic now, but will have to spend some money here defending seats.

On Labor's list of hopefuls is Deakin (Lib 3.2) in Melbourne's east, and it believes it could snare a "smoky" in the south-eastern bayside seat of Dunkley (Lib 5.6), with popular sitting MP Bruce Bilson retiring.

Outside the city it will target La Trobe to Melbourne's east (Lib 4.0) and Corangamite to its west (Lib 3.9).

But it will also have to defend McEwan to the north (ALP 0.2) and the east suburban seats of Chisholm (ALP 1.6) and Bruce (ALP 1.8).

The Coalition is worried about Corangamite.

Labor is facing a right-left pincer movement in Victoria. Here the Greens hope to pick up some seats to go with Adam Bandt's prize of Melbourne.

The outlier the Greens are excited about is Batman. The ALP holds that seat by a margin of 10.6 per cent over the Greens, rather than the Coalition.

The Greens' task will be made easier if the party can pick up Liberal Party preferences.

The Coalition view is that, if it did preference the Greens, there would be a greater than usual leakage from the ticket, given the incumbent Labor candidate, David Feeney, is from Labor's right and would be considered a moderate by Liberal voters.

Tasmania

In Tasmania, Labor will target the two northern seats of Bass (Lib 4.0) and Braddon (Lib 2.6). The Coalition will have to defend both and fears it may lose one.

South Australia

Labor's target seat here is Hindmarsh (Lib 1.9) in Adelaide's western suburbs. The Coalition concedes it is in trouble.

Northern Territory

Labor has high hopes of winning the Darwin based seat of Solomon (CLP 1.4) but the Coalition believes it will hold this seat with a good candidate in Natasha Griggs.

Western Australia

The ALP will be targeting the new seat of Burt to the south of Perth (Lib 5.2) and Cowan (Lib 4.5) to its north. But has more than a few troubles of its own in Western Australia with all three of its sitting MPs retiring.

The Coalition fears it may lose a seat here and the Greens have a long term goal of picking up Labor's seat of Fremantle.