Opposition Leader Tony Abbott is refusing to say if his party will take action against a supporter who was filmed punching a Labor campaign worker.
A campaigner for Liberal National Party candidate Wyatt Roy was filmed punching Labor supporter 22-year-old Darren Cann in the face on Saturday.
What was caught on film was "completely unacceptable" Mr Abbott told reporters while campaigning on the central coast on Sunday.
"Violence and intimidation ... have absolutely no part of this election campaign."
But the opposition refused to say if the campaigner would be disciplined, instead pointing the finger back at Prime Minister Julia Gillard.
He called on Ms Gillard to take action against Mike Brunker, Labor candidate for the Queensland seat of Dawson, who was involved in a separate punch-up on Saturday with the Bowen Turf Club president, Cyril Vains.
"While we are on the subject of people being disciplined, the Labor Party's candidate for Dawson certainly should," Mr Abbott said.
"I am prepared to apply the same standard to my candidates and to their teams that I would like the prime minister to apply to her(s).
"And I challenge the prime minister to take the toughest possible action against her candidate in Dawson."
The Labor Party is investigating the incident involving Mr Brunker.
Prime Minister Julia Gillard has urged all candidates and party supporters to behave themselves in the lead up to Saturday's election.
"Everybody should behave sensibly," Ms Gillard told reporters.
"And everybody should behave with appropriate respect to everybody who is participating in the election campaign."