Gladys Berejiklian's Coalition government is favourite with the bookmakers to retain power, but the prospect of a hung parliament is also at better-than-even odds.

If the bookies are right, Lake Macquarie independent Greg Piper will shape as an important ally for a minority government in his fourth and possibly last term.

The experienced parliamentarian has also emerged as a possible Speaker of the House, a position which would afford him the chance to improve parliamentary behaviour and, as he puts it, restore some of the public's faith in the institution.    

The Coalition and Labor also will have their attention on Port Stephens and Upper Hunter, electorates where both parties have lavished hundreds of millions on campaign promises and staged high-profile photo ops.

Both sides have also shopped around dirt files on each other to the media in the two marginal seats, including about dubious choices on social media and claims of supposedly illegal campaign material.

Outside Lake Macquarie and the two marginal electorates, Labor has wide margins in the six other Hunter seats and is expected to hold them comfortably. The Coalition is at double-figure odds in each and has gagged many of its candidates from talking freely to the media.

Held by: Kate Washington (Labor). Margin: 4.7%.

History: Two-term Liberal incumbent Craig Baumann withdrew his endorsement in 2015 over an ICAC scandal.

Challengers: Jaimie Abbott (Liberal), Bradley Jelfs (Sustainable Australia), Bill Doran (Ind), Maureen Magee (Greens), Theresa Taylor (Animal Justice).

Odds: Washington $1.33, Abbott $3.00.

"If Jaimie Abbott is not elected in Port Stephens, I don't think we will be in government."

Gladys Berejiklian left little doubt about how she viewed the Lower Hunter's only marginal electorate last month when she made one of four visits to the area since Ms Abbott was pre-selected in August.

The Liberal party has promised $205 million in new funding to duplicate more of Nelson Bay Road, the electorate's most pressing issue, $188 million to build a Fingal Bay link road and $7 million to upgrade TAFE facilities.

But the ministerial visits have dried up since Ms Abbott was forced to apologise to Ms Washington two weeks ago over accusations one of her volunteers was using fake Facebook profiles to troll the Labor campaign.

Facebook deleted Ms Abbott's profile and seven accounts connected to Tasman Brown, a parliamentary staffer for Liberal MLC Catherine Cusack.

Labor has matched the Liberal promise to spend $275 million on Nelson Bay Road in the next term of government and added another $325 million to complete the full duplication if it wins government in 2023.

It has also promised $20 million in state and federal funding to clean up drains running through the Williamtown PFAS red zone and reiterated a 2015 pledge to build a new $40 million high school at Medowie.   

The Herald has been told Ms Washington, a health lawyer, and Ms Abbott, a media consultant and Port Stephens councillor, were close in the polls several weeks ago.

Held by: Michael Johnsen (Nationals). Margin: 2.2%.

History: Has never voted Labor but came close last time.

Challengers: Calum Blair (Sustainable Australia), Lee Watts (Shooters, Fishers and Farmers), Claire Robertson (Animal Justice), Tony Lonergan (Greens), Richard Stretton (Christian Democrats), Mark Ellis (Liberal Democrats), Melanie Dagg (Labor).

Odds: Dagg $1.72, Johnsen $2.00, Watts $16.

The Nationals and their Country Party precursor have won Upper Hunter in 21 consecutive elections, but Cessnock councillor Melanie Dagg is favourite to claim the seat for Labor.

The bookies have Lee Watts, a Scone councillor and former mayor who gained almost 20 per cent of the vote as an independent in 2015, as something of a long shot.

How the electorate views her new party affiliation will be significant, but political insiders say she is not without a chance in a three-cornered contest where preference flows will be crucial.    

Labor and the Shooters will steer preferences to each other.

The Nationals' primary vote collapsed from 60 per cent in 2007 to 50 per cent in 2011 and below 40 per cent in 2015, when long-time member George Souris retired.

The Labor vote has remained stable in the low 30s for most of that time, dipped to below 20 per cent in 2011 but rebounded in 2015 with popular Muswellbrook mayor Martin Rush.

Mr Rush was seen as having a strong chance of unseating the Nationals but withdrew in January over an anonymous allegation he was involved in an altercation with a female flatmate.

Mr Johnsen had his own difficulties last year when he was threatened with bankruptcy, which would have ruled him out of the election, and a preselection challenge from Upper Hunter councillor James Burns.

Ms Dagg, a 34-year-old mother of two from Branxton, has been busy with a conga line of visits from the shadow ministry and big road and hospital funding announcements.

Labor still clearly regards the seat as winnable.

Held by: Greg Piper (Ind). Margin: 10.7%.

History: Held by Mr Piper since 2007.

Challengers: Kim Grierson (Greens), Laurance Taranto (Animal Justice), Lindsay Paterson (Liberal), Marie Rolfe (Sustainable Australia), Jo Smith (Labor).

Odds: Piper $1.12, Smith $5.25.

In one of the more curious episodes of the campaign, the Liberal parliamentary secretary for the Hunter, Scot MacDonald, praised the "strong and sustained advocacy by Greg Piper" when promising last week to spend $25 million on a new basketball stadium at Hillsborough.

Mr MacDonald's glowing endorsement of Mr Piper, who is running against the Liberals' Lindsay Paterson on Saturday, demonstrates how much the Coalition covets the independent's support to form government.

The Coalition will surrender its parliamentary majority if it loses six seats. The Greens and Shooters, who had four MPs in the previous term, are more likely bedfellows for Labor in a minority government.

Mr Piper says he has made no pre-election deals to prop up either party. He and fellow independent Alex Greenwich said last month that they would back the winner of the two-party preferred vote, rather than the party that won the most seats.

Labor appears to be lining up first-time candidate Jo Smith, the Regal Cinema manager, for another run at Lake Macquarie in 2023 if 61-year-old Mr Piper retires.

The Liberal party garnered just 16 per cent of the primary vote in 2015 in a seat the Labor party held for 57 years before Mr Piper claimed it.

Held by: Tim Crakanthorp (Labor). Margin: 7.4%.

History: The Liberals' Tim Owen resigned in 2014 over the ICAC scandal.

Challengers: Beverley Jelfs (Sustainable Australia), Charlotte McCabe (Greens), Glen Fredericks (Small Business Party), Steve O'Brien (Socialist Alliance), Claudia Looker (Keep Sydney Open), Blake Keating (Liberal), Sean Bremner Young (Animal Justice).

Odds: Crakanthorp $1.01, Keating $14.

The least safe of the Hunter's safe Labor seats is still the longest of long shots for the Liberals on Saturday.

Blake Keating is an amiable 23-year-old uni graduate with an interest in renewable energy and a directive not to engage with the media lest he damage the broader Liberal campaign.

If the Liberal party is expecting an electoral bounce from the government's $700 million investment in "revitalising" the inner-city, it is not showing it.

Newcastle's 2011 flirtation with Tim Owen and the Liberal party ended in an ICAC investigation and a 9.1 per cent swing back to Labor at the 2015 poll.

The Small Business Party's Glen Fredericks, former part-owner of the Empire cafe in Honeysuckle, launched his political career this month by incorrectly accusing Tim Crakanthorp of ignoring a domestic violence complaint.

The only other event of note in the Newcastle campaign was Ms Berejiklian's light rail launch with Transport Minister Andrew Constance last month, when their attempts to avoid questions from a Herald reporter drew condemnation in the national media.

Mr Crakanthorp's campaign promises have included $14 million for Newcastle Art Gallery, $5 million for cycleways and $3 million for the Victoria Theatre restoration.

Steve O'Brien, the only Socialist Alliance lower house candidate in the Hunter, has a policy agenda which includes rebuilding TAFE, transitioning the regional economy away from coal, better public transport, opposing seismic testing, building and maintaining the inter-urban rail fleet locally, and keeping Stockton Centre open and in public hands.

Held by: Jodie Harrison (Labor). Margin: 12.9%.

History: The Liberals' Andrew Cornwell resigned in 2014 over the ICAC scandal.

Challengers: Jennifer Barrie (Liberal), Therese Doyle (Greens), Richard Turner (Animal Justice).

Odds: Harrison $1.01, Barrie $12.

Charlestown is another of the Newcastle seats where barely a shot has been fired on the road to March 23.

Jodie Harrison secured a 22 per cent swing after preferences four years ago, putting Charlestown seemingly out of reach of the Liberals.

The only time the seat has changed hands was in 2011, when local vet Andrew Cornwell turned it blue only to come unstuck at the ICAC inquiry into illegal developer donations.

Labor has not had to make any extravagant promises in an electorate where the only polling booth to vote Liberal last time was in Eleebana.

Former Newcastle councillor Therese Doyle, co-author of a recently released book, Wrong Track, on the city's Supercars race, is the most high-profile Greens candidate in the city.

Held by: Sonia Hornery (Labor). Margin: 20.8%.

History: Always Labor since the seat was reformed in 1968.

Challengers: Sinead Francis-Coan (Greens), Toni Gundry (Animal Justice), Fiona De Vries (Australian Conservatives), Nick Trappett (Liberal).

Odds: Hornery $1.01, Trappett $14.

Wallsend has not voted anything but Labor since it was reconstituted in 1968, and 20-year-old student Nick Trappett faces an uphill battle on Saturday.

Mr Trappett is another candidate gagged by Liberal campaign headquarters, leaving Sonia Hornery a largely uncontested run to the line.

The Wallsend electorate is, however, the setting for the Coalition's biggest Hunter campaign promise, $780 million to redevelop and enlarge John Hunter Hospital, a pledge matched by Labor.   

Labor has promised $32 million to build stage two of the proposed Lake Macquarie transport interchange, a bridge spanning the rail line from Glendale to Cardiff.

Like her Labor neighbours, Ms Hornery has campaigned against changes to the Newcastle bus network after it was privatised in mid-2017.

Postal worker and Animal Justice Party candidate Toni Gundry has called on the University of Newcastle to stop what the party regards as "cruel" animal testing.

The party, which is running candidates in every Hunter electorate, says the university is "estimated to use and kill 62,000 animals a year".

Held by: Yasmin Catley (Labor). Margin: 13%.

History: Ms Catley won the then marginal Liberal seat in a landslide in 2015 after Garry Edwards was disendorsed over the ICAC scandal

Challengers: Glenn Seddon (Australian Conservatives), Julia Riseley (Animal Justice), Dean Bowman (Liberal), Doug Williamson (Greens).

Odds: Catley $1.01, Bowman $14.

Another Hunter seat which turned blue in 2011 only to fall foul of ICAC.

Ms Catley won Swansea back for Labor in 2015, having worked the previous 10 years in the offices of federal MPs Greg Combet and Anthony Albanese.

Her main campaign commitment has been to buy a state-of-the-art dredge to keep Swansea Channel permanently clear.

The Greens provided the only excitement in the Swansea campaign when Peter Morris, who was also planning to run in the federal seat of Shortland in May, quit in November over a factional war in the party.

Science teacher Doug Williamson has taken his place.

Held by: Jenny Aitchison (Labor). Margin: 13.8%.

History: Ms Aitchison won in a landslide in 2015 after Liberal incumbent Robyn Parker retired.

Challengers: James Lawson (Keep Sydney Open), Sally Halliday (Liberal), John Brown (Greens), Sam Ferguson (Sustainable Australia), Neil Turner (One Nation), Nadrra Sarkis (Shooters), Amy Johnson (Animal Justice).

Odds: Aitchison $1.01, Halliday $11.

Maitland was a Liberal stronghold, switched to Labor in 1981 then swung back to the conservatives after boundary changes and the arrival of mayor Peter Blackmore on the state political scene in 1991.

Another boundary redraw in 1999 helped Labor regain the seat, but it has flipped Liberal then back to Labor since then.

The Coalition is spending $470 million on a new Maitland hospital, but Labor incumbent Jenny Aitchison, the Shadow Minister for the Prevention of Domestic Violence and Sexual Assault, is holding a 13.8 per cent majority.

Sally Halliday is another Liberal candidate allowed limited contact with the media, despite her experience on Maitland council.

Neil Turner, a fitter machinist in the mining industry, is One Nation's only candidate in the Hunter.

Keep Sydney Open, despite the name, is running 42 lower house candidates across the state targeting lockout laws, live music and other issues it sees as important to younger voters. 

Held by: Clayton Barr (Labor). Margin: 22%.

History: Labor since 1991 but was marginal before Mr Barr's big win in 2015.

Challengers: Chris Parker (Animal Justice), Janet Murray (Greens), Josh Angus (Nationals), Steve Russell (Sustainable Australia).

Odds: Barr $1.01, Angus $12.

Clayton Barr is sitting on the biggest margin in the Hunter and looks in no danger of missing out on a third term.

The Shadow Minister for Finance, Services and Property recorded an 18 per cent swing in 2015 and is facing 26-year-old political newcomer Josh Angus on Saturday.

Behind the scenes, some Cessnock Liberals are fuming at the way the Maitland cafe owner was parachuted into the electorate as the Coalition's candidate.

Mr Angus has been off limits to the media as well, but his campaign Facebook page says he is a strong supporter of a proposed coal-fired power station at Kurri Kurri.

Steve Russell is one of five Sustainable Australia candidates in the Hunter. The party stands for better planning to stop over-development, affordable housing and a more diverse economy.