In East Hills it’s the duplexes steadily marching across the suburban landscape replacing small post-war fibro homes on quarter-acre blocks. In the seat of Penrith it’s medium density springing up near railway stations. In Riverstone it’s crowding at local primary schools, as new suburbs open up on the north-west fringe.

And everywhere voters are united in their anger about the traffic on Sydney’s roads and the lack of public transport that forces people into their cars for a long and infuriating commute to work, to school, to anywhere.

The question facing voters in south-west and western Sydney is this: has Gladys Berejiklian’s government got the right prescription for dealing with the weight of population that is straining Sydney’s outer suburbs? Would Labor be better?

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The Liberals will be showcasing the large number of infrastructure projects now under way and asking voters to be patient, that improvements are around the corner.

Labor, led by Michael Daley, will be hoping that people have forgotten its poor record investing in transport and will be promising big on hospitals, schools and measures to alleviate the cost of living.

There are only two truly marginal Liberal seats up for grabs – East Hills (0.4% Liberal) and Penrith (6.2% Liberal) – but there are a swag of other seats in the middle to outer ring of Sydney that Labor believes could swing their way in this volatile environment.

These include Oatley (6.6%), Holsworthy (6.7%), Heathcote (7.6%), Seven Hills (8.7%) Mulgoa (9.7%) and Riverstone (10.2%).

Once safe territory for Labor, the middle and outer rings of western and south-western Sydney have become the battleground due to demographic change and efforts by the Liberal party to appeal to what the former prime minister John Howard called his “battlers”.

A raft of seats swung to the Liberals federally in the 1990s but some have swung back.

At the state level, these areas were mostly safe Labor until 2011, when the electorate delivered a thumping defeat to the Keneally government. Tired of corruption scandals and lack of action on transport, the middle and outer suburbs of Sydney punished Labor with swings of up to 27%.

Some like Strathfield, Granville and Campbelltown have returned to Labor, but the Liberals still hold half a dozen seats with solid margins.

Facebook Twitter Pinterest Cameron Murphy is Labor’s candidate for the seat of East Hills. Photograph: Carly Earl

The best prospect for Labor in 2019 is East Hills, where Cameron Murphy – a barrister and son of former high court judge Lionel Murphy – is running again against a new Liberal candidate, Wendy Lindsay, who was head of a local P&C.

According to Murphy the big issue is overdevelopment. In East Hills, streets of suburban fibro homes on large blocks are being replaced by large duplexes with just one garage.

“The problem it’s creating is the streets are full, because the duplexes usually have four or five bedrooms and most people use the garage for storage. Emergency vehicles, garbage trucks can’t get down the street. In some parts of the electorate, the council has put in no stopping between 6pm and 6am,” he says.

“I think everyone accepts that Sydney is a growing city but it’s not being shared across the city fairly. That’s the problem people have. We are not getting any infrastructure to go with it,” he says.

Murphy says that voters are concerned the area will lose its charm as a suburban pocket just 20km from the city.

Facebook Twitter Pinterest Duplex properties next to older style homes in Revesby. Photograph: Carly Earl

One longtime resident of Padstow, Ken Tyrell, summed up his discontent at change in East Hills, as he waited for his fish and chips at the local shop.

“It was a pretty good suburb, Revesby,” he says. “Even 20 years ago.”

“I loved the place, but I have seen it degraded. It’s now unliveable, it’s overpowering,” he says.

Tyrell believes the issue underlying it is overpopulation, and though he’s normally a Liberal voter, he says he’ll take a good look at One Nation this time around.

Infrastructure is under stress. Schools have demountable classrooms, the trains are full and the main roads congested, Murphy says. He now leaves increasingly early to get to work in the city, he says.

Facebook Twitter Pinterest Parking congestion in Revesby. Photograph: Carly Earl

And then there is the issue of cost of living: tolls, electricity bills and rising house prices that make it difficult to buy into the area.

Lindsay, the Liberal candidate, acknowledges that the duplex development is an issue but says it’s one for council and that good design is what’s needed. She also points out that the villages that make up her electorate – Revesby, Padstow, Panania – will only survive if there is enough population to keep local businesses alive.

She points to the Liberals’ record: the M5 duplication of the tunnel is getting close to opening; there’s been $25m invested in Bankstown hospital and a mobile ServiceNSW centre at Revesby.

Facebook Twitter Pinterest Wendy Lindsay is the Liberals’ candidate for the seat of East Hills. Photograph: Carly Earl

Last election Murphy was the subject of an ugly smear campaign in which his posters were defaced and anonymous leaflets distributed insinuating that because he was a former chair of the Civil Liberties Council he was a protector of paedophiles. He’s hoping for a cleaner fight this time.

Cost of living

The second most marginal seat in western Sydney is Penrith, held by the Liberal sports minister, Stuart Ayres.

As the man responsible for the unpopular decision to knock down Allianz stadium and extensively rebuild Homebush stadium at a cost of $1.5bn, one might expect he’d be feeling the pressure.

Quite the contrary. “The main thing I hear is why isn’t Penrith getting one,” he says of the local reaction.

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“I think people know when they travel into the city to a game that Allianz is old and doesn’t meet standard,” he said.

He also points to the new 30,000-seat western Sydney stadium at Parramatta that will open in April.

Penrith used to be Labor heartland – Ayres himself says it’s socio-economically smack bang in the middle of middle Australia – but somehow it’s drifted away.

Facebook Twitter Pinterest Stuart Ayres, the Liberal MP for Penrith, outside his electorate office. Photograph: Carly Earl

“I think Penrith remembers that Labor didn’t do anything, they took them for granted. But there are a lot of new voters in Penrith and they are concerned about working closer to home and we are working on that,” he says.

The Coalition has lavished resources on Penrith. The Northern Road and Mulgoa Road are being widened, there’s a new commuter car park at Penrith station, and the government announced a $1bn upgrade of Nepean hospital two years ago which is now under way.

Last week the government announced (at Nepean) 5,000 new nurse positions and some of these will go to relieving the chronic shortage of staff and the long waiting lists at Nepean.

Ayres also points out that the west and Penrith are home to a lot of tradies and construction workers and they have been benefiting from the billions being spent on Westconnex. But with the Westconnex project also comes disruption and tolls.

Karen McKeown, a longtime councillor on Penrith council, is running for Labor.

Aside from parking in Penrith – arguably a local government issue – the big issue is the cost of living.

“It’s the nitty-gritty of the power bill coming in, back to school costs, and how do we cope. The tolls come up heavily,” McKeown says.

Facebook Twitter Pinterest Councillor Karen McKeown is Labor’s candidate for Penrith. Photograph: Carly Earl

Tolls reintroduced since the M4 was widened are based on distance and range from $1.91 to $4.93. But there will be more tolls once the M4 east – a tunnel section from Homebush to Haberfield – opens.

McKeown says that 65% of Penrith residents travel east for work either by train or road so it’s a big impost.

“Its $2,000 a year,” she says of the new toll. “That’s the difference between a new computer, or taking the kids on a holiday,” she says.

Labor has promised a cashback scheme, similar to the M5 cashback as part of its suite of policies to alleviate cost of living pressures.

McKeown says the cost of power comes up time and again while doorknocking. “They remember the poles and wires privatisation,” she says.

And then there is the issue of overdevelopment. In Penrith it’s manifesting mainly as eight- to 12-storey unit blocks near stations. McKeown says there is a sense that western Sydney is bearing an unfair burden of housing the growing population.

Roads and rail

In the south-west the issues are also about infrastructure and development. But Melanie Gibbons, the Liberal member for Holsworthy, is banking on her voters recognising what the Berejiklian government has done to improve infrastructure, rather than dwelling on the possible cost impacts of tolls.

The multicultural seat straddles Liverpool and Prestons but runs south into the shire which is safer Liberal territory. The other two seats of Oatley and Heathcote on single-digit margins are also in the shire.

Gibbons points to the government’s rail upgrades and new commuter car parks at Edmondson Park and Casula as proof that the government is meeting the challenge.

Facebook Twitter Pinterest The Liberals’ Melanie Gibbons is attempting to hang onto the seat of Holsworthy which she holds with a margin of 6.7%. Photograph: Anne Davies/The Guardian

‘“It’s an exciting electorate to represent,” she says. “You can fight for car parks for commuters, fight for hospitals, for schools and jobs to keep them close to their homes,” she says.

As for whether there is any blowback from the M5 duplication project, Gibbons says people are just looking for quick and easy ways to get home.

“They often comment how silly it was the M5 was only built with two lanes each way, so I think they are just happy to finally see it fixed,” she says.

Demountables and overcrowding

In the north-west of Sydney it’s the new suburbs of detached houses that are both changing the character of the electorate and adding to the stresses and strains.

The local children’s GP Dr Annemarie Christie is running as Labor’s candidate, against the sitting MP, Mark Conolly, in Riverstone where young families moving into new suburbs have turned the old safe Labor semi-rural seat into a safe-ish Liberal seat.

Christie is determined to put it to the test and attempt to get at least a 10.2% swing.

“Schools are a major issue because there are so many kids here,” she says. “We have more demountables in our schools than any other electorate. Some of the children in our electorate will go through 13 years of school without ever seeing the inside of a proper classroom,” she says.

Christie says that some of the schools have been open for just five years and are already at capacity, raising serious questions about why the government’s planning has failed the area so badly.

Facebook Twitter Pinterest Dr Annemarie Christie, Labor’s candidate for Riverstone, hopes to take the north-west seat from the Liberals. Photograph: Anne Davies/The Guardian

The Ponds high school, for instance, opened in 2015, and has had a staggered intake to year 10. But it’s now full and there are two more years of intake to come: 800 students, says Christie.

“In two years time that brand new high school will have 50 demountables. At the same time a block of land earmarked for a high school was sold off, because they said they wouldn’t need it.”

Then there’s the issue of hospitals, also close to Christie’s heart. The government has announced plans for a new hospital at Rouse Hill, but for the foreseeable future the voters in the north-west will be making the 20km trek to Westmead.

Berejiklian has been calling for an immigration reduction as part of her solution to Sydney’s growing pains. But her key message is: we’ve been building things.

In the north-west, her government is now testing the new metro service between Rouse Hill and Chatswood. It should be open in April.

Daley will be focusing on what she hasn’t done, particularly in the area of schools and hospitals, and arguing that the west is taking an unfair burden to house Sydney’s population.

It will be a tough ask to win back the swag of seats he needs, but he must win in the west if Labor is to have any chance of regaining government – this election or the next.