Ms McKenzie and any other hopefuls have until February 1 to nominate.

Speculation around the senator has been growing since she relocated her office to Wodonga late last year, but as of Monday, she had not made an announcement.

The Nationals’ 2016 candidate Marty Corboy, who won 17.2 per cent of the first-preference vote after the party’s first election campaign in Indi in 15 years, has not ruled out trying again.

“I’d be lying to say I hadn’t thought about it. I thought we did very well at the last election with 18 per cent of the vote,” he said.

“I would be honoured to have that opportunity again.”

But Mr Corboy said he would consider his options before making a decision before the February 1 deadline.

With independent Helen Haines and Liberal Steve Martin replacing Cathy McGowan and Sophie Mirabella as candidates, Mr Corboy said the 2019 election would bring a generational change.

“I think we will hold our own. We have a base now of 18 per cent, we just have to grow that,” he said.

National Party Victorian state director Matthew Harris took aim at Voices for Indi’s closed selection meeting this month.

"Unlike the Voices for Indi political party with their opaque pre-selection process, where the community didn't even know who the candidates were, the Nationals have always believed in genuine, transparent, on the ground democracy," he said.

If more than one candidate nominates, the Nationals will hold a pre-selection vote for Indi members on February 16.