Labour is demanding an apology from National after a video emerged showing its Mt Roskill candidate in Auckland did not commit assault.

Michael Wood was facing accusations of assault on National candidate Parmjeet Parmar's husband after he made comments about his wife.

The video shows a war of words between Mr Wood and Mr Parmar, but no physical contact.

Mr Wood said it's another case of dirty politics.

"The video shows that I did not touch the man, so we're calling on the National Party to apologise and desist from these kinds of slanderous lies, and get back to a positive campaign," he said.

"We've been running a positive campaign, which has been very issues-based, focused on putting up positive solutions around transport, around housing, crime, education - that should be what all candidates are focused on."