Former prime minister Tony Abbott has defended eating a raw onion in 2015, while downing a whisky with Sky News' Andrew Bolt on Thursday.

"What was going through your mind there?" Mr Bolt asked Mr Abbott during a relaxed interview.

"Well, I was at a Tasmanian farm and the farmer understandably was incredibly proud of his produce," Mr Abbott said.

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"All of us eat raw onion occasionally. Salads are full of raw onion. This was an onion that had lost all of its outer skin. It had in-effect been peeled," he said.

"So I thought the least I can do, for someone who was as proud of his product as this particular farmer, was take a chomp. It was beautiful. Absolutely beautiful."

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Mr Abbott said one of the jobs of the prime minister is to be "the country's cheerleader in chief" and that he or she should "do what you can to show your appreciation for your fellow Australians".

Mr Abbott served as prime minister from 2013-2015 before being unseated by Malcolm Turnbull.

In December, he said he may push for a frontbench position if the Coalition wins the next election, and would not rule out another tilt at leader.

But the former prime minister is facing a tough fight to retain his seat of Warringah, with champion skiier Zali Steggall running as an independent.