Mr McCormack had been in town meeting with Cowra councilors to identify infrastructure projects that could be addressed if the coalition was returned to government.

Addressing the members, there was not much love for the Greens, with lower house MP Adam Bandt receiving a ribbing for wanting to shut industry down, with a harsher jibe reserved for one of his Senate colleagues.

"Sarah Hanson-Young - what a complete loser she is," Mr McCormack said.

He pointed out how senators often came under fire from former Labor prime minister Paul Keating.

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"Most of them you've never heard of, most of them you wouldn't have home for a barbecue," he said

"I didn't agree with much Paul Keating said, but he did call it unrepresentative swill. He was probably right then, it's probably true today."

With a series of three-cornered contests pitting the Nationals against the Liberals this election, Mr McCormack couldn't resist a crack at big brother's candidate in the NSW seat of Gilmore.

"The Libs have parachuted Warren Mundine in from the eastern suburbs of Sydney despite the fact the Liberals pre-selected at a local level Grant Schultz," he said.

Mr McCormack also said the current Labor leader would make Julia Gillard look like a Sunday school teacher if elected.

"Bill Shorten's initials aren't BS for no good reason."

While punters rarely raise the issue of preferences with the Nationals leader, one woman wanted some answers after hearing about them on morning radio.

READ MORE: Early voting for Cowra residents opens on May 11

After outlining his approach in his own seat - the Greens go last unless a "complete nut-job" runs - he launched a defence of putting One Nation above the opposition.

"Why be all ideological and pure and sit in opposition for three years?" Mr McCormack asked.

"I've been in opposition and I know how lonely and desolate it is when you have to march cap in hand to someone like Chris Bowen and ask for funds."