One of Australia's top political scientists says the 2019 Federal Election is likely the first in the Mallee where preferences will determine who wins.
Dr Nick Economou, a senior lecturer in politics international relations at Melbourne's Monash University, said the impact of outgoing Member for Mallee Andrew Broad's conduct as well as all the major parties running candidates would mean the traditionally safe seat might not be won on a primary vote.
Prime Minister Scott Morrison has announced the 2019 Federal Election is on Saturday, May 18.
Dr Economou said there was potential for an independent to win Mallee, though it would be difficult for them to gain a region-wide profile.
"If you have a contest where the Liberals, Labor, Nationals and a popular independent are running, that is a four-way split of the primary vote," he said.
"One thing for certain is whoever wins Mallee this year will win it on preferences. I'm not confident to call Mallee for the Nationals, given the result of November's state election in Mildura where independent Ali Cupper beat incumbent Nationals MP Peter Crisp."
Andrew Broad won Mallee with a swing of 25.6 per cent at the 2016 election, but he declared he would stand down after news that the married MP had dinner with a woman he met on a 'sugar-baby' dating website while on a trip to Hong Kong became public.
Dr Economou said it was hard to prove Mallee had missed out on investment due to its status as a safe seat.
"When the independent candidates are running around alleging National Party negligence, there has to be some sort of context in which that resonates for voters to be able to take that seriously," he said.
"I'm assuming the reason the allegation is resonating now is not because of failures on water and infrastructure provision - they may well be there - but I suspect the election is around the personal behaviour of the MP.
"Cathy McGowan won Indi (in north-east Victoria) in 2013 - not because of any demonstrable sense there was an unequal distribution of resources to Indi relative to anyone else, but because people didn't like (sitting Liberal Party candidate) Sophie Mirabella."
Dr Economou said the Nationals' stronghold on the Mallee reflected its farming roots.
"My feeling is the part of Victoria further north is a much harder place to farm, and it's actually quite reliant on government-provided infrastructure - especially irrigation, rail transport bringing commodities to port and roads," he said.
"That is what the Country and National parties used to be quite good at delivering."