By Tom Westbrook
MILDURA, Australia (Reuters) - A conservative stronghold for a century, Australia's hinterland is now cracking like the drought-parched earth, voters say, with once-safe districts in jeopardy ahead of Saturday's election.
Driven by anger on issues from climate change to water allocation, the splintering presents a problem for the governing conservative coalition that normally considers itself secure in rural areas but is trailing in national opinion polls.
In Mildura, a city of 30,000 people on the edge of the outback and part of the safest of 16 electorates held by the coalition's junior partner, the farmer-based National Party, nobody can recall it ever needing to campaign so hard.
"If you just look at the distribution of posters, they're up everywhere," Stefano de Pieri, a politician-turned-chef who has run a restaurant there for almost 30 years, told Reuters from his kitchen by a bend in the Murray River.
Mildura was one of five constituencies to spurn the Nationals at state polls in November and March, its disillusionment stoked by a deepening drought and a feeling the 99-year-old party of "the bush" was taking voters for granted.
"There is a sense of Mildura wanting to go through a political renewal," de Pieri added, a contrast from previous years, when the Nationals were seen as sure-fire winners.
In the agricultural heartland beyond, the mood is similar.
"Everyone I've talked to is not going to vote National Party," said Leonard Vallance, the livestock president of the Victorian Farmers' Federation.
"They need a good shake and I think they'll get it," Vallance said by telephone from his farm south of Mildura where he grows wheat and barley.
"I will be lodging a protest vote. It definitely will not be Liberal Party or National Party or Labor Party."
Seat-by-seat polling is tricky in vast and varied electorates sprawling over cropland, grazing runs, orchards and family farms.
But nationwide surveys put the opposition Labor Party ahead, and bookmakers suggest contests are tight in Mallee, which takes in Mildura, and in similar seats nearby, are tight.
The coalition holds 73 of the 151 seats in Australia's lower house, and Labor 69, with 76 needed to govern. [nL4N22S0ZW]
Betting markets suggest the Nationals will retain Mallee with a reduced margin but the coalition could lose the neighbouring electorate of Farrer for the first time since it was established in 1949.
Few independent candidates are likely to back the Labor Party into power because social conservatism runs deep in their constituencies, but they have said the Nationals' policies on mining, climate change and water are inadequate.
Party leader Michael McCormack said contests could be hard-fought when the incumbent was stepping down, as in Mallee, where the MP resigned after a sex scandal.
"Nationals never take for granted the voters of the Mallee," he said in comments emailed to Reuters, adding that the party was responding to voter concerns with steps such as a re-examination of the region's water allocation plan.
"The Nationals'...grassroots structure ensures we can allocate resources where needed to run seat-by-seat campaigns."
But spending to shore up safe districts saps funds for other contests in an election where the government must win additional seats to keep power.
"Even if they don't lose the seat they've lost resources elsewhere, which might contribute to a loss elsewhere, so it is very significant," said Dominic O'Sullivan, a political science professor at Charles Sturt University in Canberra, the capital.
"It also shows the Nationals are perhaps not as well in touch with their communities as they once were," he said.
The party has struggled in recent years to parlay its status in the ruling coalition to win benefits for farmers, he added.
With swathes of the countryside gripped by the driest conditions in 100 years, voters feel they need a strong voice more than ever.
After Australia's hottest summer on record, the drying-up of the Darling River, which winds through 1,500 km (900 miles) of outback, over grazing country and irrigating crops from cotton to grapes, has stirred discontent.
Many feel National Party support for a water allocation plan that drained reservoirs upriver in flood years has worsened the drought, prompting protests.
"People here deal with water. Water is their livelihood," said Lance Tumes, who runs a hardware store and petrol station on the banks of the Darling where it meets the Murray River just outside Mildura.
"I think the Nationals have just treated them like mugs, and I think they've had enough," he said.
(Reporting by Tom Westbrook; Editing by Clarence Fernandez)