UPDATED 6.40PM Labour's Mt Roskill by-election candidate Michael Wood is denying accusations of assault.

The assault is allegedly on the husband of Parmjeet Parmar, the National candidate for the Auckland seat.

Parmjeet Parmar told the NZ Herald Mr Wood had lost his cool after appearing to get "rattled" during a public debate on Wednesday night.

LISTEN ABOVE: National's Parmjeet Parmar spoke with Larry Williams

That came after heckling from Parmar's husband, Ravinder, and other National Party supporters sat in the front rows of the Three Kings Community Centre.

Wood is denying physically touching Mr Parmar, but has admitted there was a "robust" altercation.

Mr Wood said after the debate he confronted Mr Parmar and told him his language was unacceptable, after derogatory comments were made about Mr Wood's wife.

"There was absolutely no physical altercation between me and Mr Parmar, none whatsoever, the allegations I held him in a hold are utterly bizarre."

Mr Wood is calling on Ms Parmar to stop the personal attacks on him and his family and focus on the real issues affecting Mt Roskill.

"Very simple - I just want their campaign to actually focus on debating about the issues. I've got no issue whatsoever with this being a very robust campaign if it's about the issues that affect people here."

Mr Wood said he is not a robot and if someone attacks his wife in a political environment he will respond to it.

However, Parmjeet Parmar told Larry Williams there was no attack on Mr Wood's wife.

"If simply saying his wife is on the local board is an attack, then he is under more pressure than it seems," she said.

Parmar said she didn't witness the incident, but others did. She said Mr Wood lost it.

"It looks like my opponent is going to attack people that just state facts he doesn't like, and that was a massive overreaction from him. An unacceptable overreaction from him."