Barnaby on what women want

He had his wife by his side for the first time in the campaign but don't ask Barnaby Joyce what women want.

"I tell you what, there was a fellow who made a movie about that and he turned out not to be very successful - so let's not go there," the deputy prime minister joked, referring to the 2000 Mel Gibson flick.

Mr Joyce was being quizzed about recent Newspolls showing women voters could be key to winning the election.

The Nationals leader added that all constituencies mattered - and warned voters not to experiment with Labor as he took his campaign on Tuesday to the safe seat of Parkes in western NSW.

Accompanied by wife Natalie in her election campaign debut, Mr Joyce spruiked the government's commitment to the inland rail project.

The coalition has pledged $594 million in the budget for pre-construction work to boost the freight link from Brisbane to the southern states, which farmers have long been lobbying for.

Mr Joyce said the project was nation-building and would create a "corridor of commerce".

The money was a rock-solid commitment it would finally be realised and would allow the national interstate rail body to buy up property for track-laying.

"You can't just have a farmer wake up in the middle of the night and say, 'Doris did we have a railway line in the middle of our paddock last night? Nah? Well, it's there now'," the minister told reporters in the regional town of Narrabri.

"You've got to actually purchase it off them."

Former deputy prime minister John Anderson, who has pushed the government to commit to the project or dump it altogether, is satisfied it's finally kicked-off.

The former Nationals leader has authored a study into the project for the government and wants to see it happen within eight years.