Tony Abbott, former PM, says he is quietly confident of winning his election seat

FORMER LEADER VOTES: Former prime minister Tony Abbott admitted to having butterflies in his stomach as he cast his vote.
FORMER LEADER VOTES: Former prime minister Tony Abbott admitted to having butterflies in his stomach as he cast his vote.

A nervous Tony Abbott has urged voters not to reward the kind of "nasty" behaviour that saw one of his volunteers stabbed with a corkscrew on the eve of the election.

The former prime minister lamented the ugliness that has dogged his campaign after casting his vote alone at Forestville Public School in his Sydney seat of Warringah.

He faces the fight of his political career against independent Zali Steggall, who many pundits rank as favourite.

Mr Abbott suffered a nine per cent primary vote swing against him at the 2016 election and holds the seat with a strong 11 per cent margin.

Asked by a voter whether he will win on Saturday, the ex- Liberal leader said he was not too cocky but quietly confident.

"I've always been a nervous candidate," he said after casting his ballot and buying a loaf of banana bread from the school cake stall.

"Sure, I've got a few butterflies doing loop-the-loops in my tummy today as well. But that's the lot of all candidates because the one thing you can never take for granted is the vote of the Australian people."

Mr Abbott - who was criticised for saying that deceased Labor leader Bob Hawke had "a Liberal head" - said it had been an ugly campaign.

Mr Abbott said there many low blows, culminating in an attack on a Liberal Party volunteer while erecting posters at a polling booth in Balgowlah on Friday night.

The 31-year-old was allegedly stabbed in the stomach with a corkscrew, causing a minor injury. He was back at his post on Saturday, Mr Abbott said.

"Lucky he wasn't seriously hurt," he said.

"My message is the voters of Warringah should not reward this kind of really low and vicious behaviour. I'm not saying that any particular candidate is behind this, but there's absolutely no doubt who these people want to beat."

The alleged 62-year-old attacker, who also tore down banners, was later arrested and charged with two counts of common assault.

Ms Steggall said the incident was appalling but she did not believe the alleged culprit was linked to her campaign.

"We have checked and I don't (believe) that they are. I would be extremely shocked and extremely disappointed (if they were)," she told reporters.

"We should be respecting everybody."

The Olympian visited a number of polling booths on Saturday before casting her vote alongside husband Tim Irving at Balgowlah North Public School.

She said voters were ready for change and believed dethroning Mr Abbott after 25 years in the seat was achievable.

"I'll take my read from the people I'm talking to and they are confident for change," she said.

"People want to hear positive messages, they want to hear policies. They don't want to see smear campaigns."

A number of posters of Mr Abbott outside the school at which he voted had been defaced with a Hitler moustache, which volunteers tried to rub off before polls opened.

Australian Associated Press