An attack on a Liberal Party volunteer with a corkscrew in his seat of Warringah on Friday night, was 'low and vicious behaviour', former Prime Minister Tony Abbott said.

Key points: The accused allegedly threatened one man and thrust a corkscrew into the stomach of another at a public school in the seat of Warringah

The accused allegedly threatened one man and thrust a corkscrew into the stomach of another at a public school in the seat of Warringah A 62-year-old man was charged with two counts of common assault and granted bail

A 62-year-old man was charged with two counts of common assault and granted bail The attack was part of an ugly campaign in his seat, local MP Tony Abbott said

A number of volunteers were putting up campaign posters at a polling booth outside Balgowlah Heights Public School about 8:00pm when a man began yelling abuse at them, police said.

"He allegedly threatened an 18-year-old man before he thrust a corkscrew at the stomach of a 31-year-old man causing a minor injury," NSW police said in a statement.

"He then started ripping down the banners that had been erected, before fleeing the scene."

The injured man was treated at the scene by paramedics but was not taken to hospital.

Mr Abbott, who voted at Forestville Public School in Sydney this morning, described the incident as part of an ugly campaign in Warringah.

"I think we've seen a lot of low blows. And last night, we saw a most unfortunate incident where one of my campaign volunteers was attacked and stabbed," he said.

"Now, luckily, he wasn't seriously hurt. He's back at his post today."

Mr Abbott did not blame any other candidate for the attack, but said he believed he was the target.

"But my message is, the voters of Warringah should not reward this kind of really low and vicious behaviour," he said.

"I'm not saying that any particular candidate is behind this. But there's absolutely no doubt who these people want to beat.

"And I say to the people of Warringah, think long and hard before you give these nasty elements in our polity the victory they want."

Assault charges laid over attack

Mr Abbott's seat of Warringah has been in the spotlight during the election campaign. ( AAP: Dean Lewins )

Footage uploaded to social media showed a man tearing a Liberal Party banner off a fence before calling a political volunteer a "paedophile supporter".

A person filming the confrontation asked the man: "What are you doing that for sir?"

"It's my democratic right," he replied.

A photo taken after the incident showed the quiet north-Sydney street lined with police vehicles and officers.

A man was found by police in a nearby home two hours later and taken to Manly Police Station.

The 62-year-old was charged with two counts of common assault and granted conditional bail.

He has been ordered to appear before a Manly court next month.

The former prime minister holds Warringah by a margin of 11 per cent but faces a strong challenge from former Olympian Zali Steggall.