TONY Abbott and Kevin Rudd don't agree on much, especially during an election campaign.

But they were united on Tuesday in sympathy for Liberal candidate Jaymes Diaz.

Both men leapt to Mr Diaz's defence after he was left red-faced in a television interview on Monday night.

In the five-minute interview, the Liberals' hope in the west Sydney seat of Greenway is unable to detail the coalition's six-point asylum plan.

"The key point would be stopping the boats where safe to do so," is Mr Diaz's best reply to questioning from Network Ten's John Hill.

Mr Abbott was quick to defend his candidate over the interview, which has since gone viral on YouTube.

"I'm afraid it happens to all of us from time to time," he told ABC radio in Sydney.

He said an occasional gaffe was just part of being in politics.

"Inevitably, a very experienced and slightly aggressive journalist shoves a microphone in your face and starts barking at you and it is possible to freeze," he said.

"I've done it myself."

Prime Minister Kevin Rudd, too, was in Mr Diaz's corner.

"I understand the Liberal candidate for Greenway had a few challenges yesterday. I'm sure some of ours will at some stage or another," Mr Rudd told reporters in the Queensland seat of Griffith.

"That's just life in an electoral campaign. If you've been through as many as I have you've seen anything happen."

Mr Diaz, a local family lawyer, is running against Labor's Michelle Rowland, who holds Greenway on 0.9 per cent.

Mr Diaz did not return AAP's calls.

Deputy Prime Minister Anthony Albanese said although it was the first gaffe of the 2013 campaign, it wouldn't be the last.

"I think anyone who's never made a mistake ever is entitled to have a go," he told reporters in Sydney on Tuesday.

But he said it was important that politicians were able to support the policy of their party.

"Particularly when there's not much there to support," he added.

"This person's been a candidate before of course.

"He was chosen by the Liberal Party last time around, they've selected him again, they obviously think he's one of their best."

The coalition needs a swing of just 0.9 per cent to claim the seat from Labor MP Michelle Rowland, making it the most marginal in NSW.

Originally published as Rudd, Abbott back Lib candidate over gaffe