Mr Barilaro is not ruling out a switch after rumours Labor MP Mike Kelly could quit and trigger a by-election in his regional seat of Eden-Monaro.

While Mr Kelly has dismissed suggestions he's leaving politics, speculation has been rife about the NSW Nationals leader's federal ambitions.

Mr Littleproud, the federal water minister, said he would be happy to see Mr Barilaro in the federal party room despite his threats to leave the Murray-Darling Basin Plan.

"We would like to see a National Party member in Eden-Monaro," Mr Littleproud told AAP on Tuesday.

"If Mike Kelly goes, or at the next election you may see John Barilaro wants to transition, you may see him as a National Party candidate.

"We need to win Eden-Monaro back and we can win it back."

He said Mr Barilaro and NSW Water Minister Melinda Pavey were passionate advocates for their state.

"The fact that Melinda Pavey and Barra have gone out there passionately supporting irrigators is a good thing," Mr Littleproud said.

"That's a healthy thing in democracy. You don't want a cookie cutter approach where we all agree.

"Shouldn't we want diversity in a party room where different ideas and values come in and we can debate them?"

But the federal water minister insists sticking with the Murray-Darling Basin Plan is the best option.

"Do people really want to walk away and pause this and then leave it for a future Labor government?" he said.

NSW Liberal Premier Gladys Berejiklian last month joined other state leaders in endorsing the plan despite her coalition partners agitating against the long-standing agreement.

Australian Associated Press