Act candidate John Boscawen was accosted with a chocolate and cream lamington as a Mt Albert byelection debate yesterday descended into farce.

Malcolm France, a candidate for People Before Profit, attacked Mr Boscawen with the cake as a protest against the Super City.

The confectionary sat on Mr Boscawen's head while he continued to address the crowd, saying he didn't want to waste his allotted time to speak.

Mr France was later escorted from the debate at the Unitec Institute of Technology.

"Yes, when I was speaking I had a person come and squash a lamington on top of my head," Mr Boscawen said afterwards. The rest of the debate went well, he said.

The blunder-prone National candidate Melissa Lee also came under fire. She faced questions over an email in which she was alleged to have said she wanted "a big diamond ring ... to knock some sense into the media (although a gun is tempting)".

The email was a response to a question posed by a magazine, which asked: "Which accessory would you choose: a gun, a fur coat, a big diamond ring or a grill?" Ms Lee said the email was written by a volunteer staff member who wanted to add some humour.

Student activists, who branded her a racist at a debate at Auckland University last week for her claim that a Waterview motorway would divert criminals from South Auckland, continued to taunt her. In response to a question about what she would do if she wasn't in politics, the mainly Polynesian group shouted that she would be "on a plane back to Korea" and she could "become the racist relations commissioner".

Other candidates who took part in the debate were Labour's David Shearer and Green Party co-leader Russel Norman.

Dr Norman said the people in Mt Albert were used to having a party leader as their MP and should vote for him if they wanted that to continue.

Mr Shearer said that since he was the only non-list MP among the main candidates, voters could be certain about who they would get to represent them if they voted for him. "Vote for me and you get me. Not some dentist from Manurewa or a Green Party candidate you've never heard of."

Mr Boscawen said the byelection was a two-horse race between himself and Mr Shearer and he was the only right-wing candidate worth voting for.

Mr France later said his lamington attack was "a statement against Act's support for National in the Super City".

The end of the debate didn't end Ms Lee's problems. She left the venue to find her car clamped in the carpark.