The federal government's $10 billion, 1700-km Brisbane to Melbourne inland freight rail project has hit a nerve for some farmers in the NSW electorate of Parkes.

While water is a regional issue garnering national attention, these disenchanted voters believe inland rail could open up another front against the Nationals.

"I think it is hurting them. I think in the Barwon area you've seen it already," Wanda Galley told AAP

"It is predominantly because of inland rail and the way they're handling it."

Her property is between Burroway and Curban, northwest of Dubbo, while Jennifer Knope of Narromine also raised concerns with Nationals leader Michael McCormack at the Gilgandra show.

At the heart of their concerns is the consultation process.

Mr McCormack says he took decisive action to improve consultation once he took over the portfolio.

"People whose farms are going to be impacted are always going to be concerned. I understand that," he told AAP.

"But we have to sometimes look at the overall benefits to communities, to regions, to states and the nation overall.

"If we just said we're not going to build anything because it's going to have an affect on some people, we would never build anything in this nation."

Scott Morrison's circus swept through the show while his deputy met punters with less fanfare.

Mr McCormack doubled back to the protesters after the limelight of the first prime ministerial visit to the town faded.

He delayed his next campaign stop to listen to their concerns but they appear to be fighting a losing battle.

Gilgandra is in the seat of Parkes, where local MP Mark Coulton is a popular figure.

That could ward off any significant damage to his 15.1 per cent margin, despite the Nationals copping a whacking at the state election.

The opposition has promised an inquiry into inland rail's route selection and financing model if Labor wins government on May 18.

Speaking to the protesters, Mr McCormack points out the political expediency in Labor's announcement coming smack bang in the middle of the election campaign.

Ms Knope, who lives at Narromine where a significant section of the line stretches to Parkes, has vowed to keep up the fight.

"They've got to address at least three major floodplains. They have underestimated the cost. Their costings are pathetic," she told AAP.

A CSIRO report found if road trips switched to inland rail it could save an average of $76 a tonne.

"We need to get on and build because this has been demanded for more than 100 years," Mr McCormack said.

Ms Galley said fourth generation farmers had not been consulted properly about the route.

"We just feel they're not listening at all," she said.

"Everybody's talking about the issues and the problems, why aren't the politicians listening?"

Australian Associated Press