BARNABY Joyce is so sure Tony Abbott will still be prime minister at the next election that he'll bet his house on it.

"I put money on it, we won't be talking about this issue at the next election," the agriculture minister told ABC TV on Thursday.

He said voters would have forgotten what happened on Australia Day, when the prime minister was ridiculed for his decision to confer a knighthood on Prince Philip.

"It will be lost in the fish-and-chip wrapper where it belongs," Mr Joyce said.

The Nationals deputy leader is among a number of senior government figures publicly supporting Mr Abbott as leader as the fallout from his "captain's call" continues.

That's despite some of his biggest backers, including conservative columnist Andrew Bolt, questioning the PM's judgment.

But Mr Joyce said the "mistake" proved Mr Abbott's authenticity as a person.

"When they are authentic you can trust them," Mr Joyce said.

"If I've got a dentist with a drill in my mouth, I don't care if their friends think they are a cracker or their friends don't like them."