The NSW Nationals leader John Barilaro has begged his federal counterparts to "shut up" as a sensational outbreak of infighting threatens to damage the party's prospects in a knife-edge state election campaign.

The Deputy Premier's plea came as tensions in the federal Coalition escalated after deputy Nationals leader Bridget McKenzie said Australians were "frustrated" by former leader Barnaby Joyce freelancing on energy policy with his call for a new government-backed coal power station.

NSW Deputy Premier John Barilaro said his federal colleagues should "just shut up". Credit:Alex Ellinghausen

Mr Barilaro is struggling to hold on to key Nationals seats across NSW ahead of the March 23 poll, including Lismore and Tweed in the state's north, and his own division of Monaro.

He said his federal counterparts were not helping and advised them to stop airing grievances over coal and the leadership of Deputy Prime Minister Michael McCormack.