Conservative Party leader Colin Craig thinks John Key is "too gay" for his Helensville seat and has said so in 20,000 letters to residents.
Pamphlets arrived in locals' mailboxes this week, urging them not to back Labour MP Louisa Wall's same-sex marriage bill. They were accompanied by a signed letter from Craig. It gave prominence to a comment from a disgruntled local: "Colin, you should stand here because John Key is too gay for Helensville."
Craig says people have expressed disgust that their local MP was supporting the bill without asking their views.
"MPs have a duty to represent their electorate but John Key has chosen to ignore the views of the people of Helensville and carry on regardless.
"I was in the town a few weeks ago and was surprised at how many people were annoyed that he is not listening to them.
"There are people out there who simply don't like to see their Prime Minister doing things like dancing on stage with transvestites, as he has done in the past," he said.
Key - who wore a pink shirt at a meeting with US Secretary of State Hillary Clinton in the Cook Islands yesterday - said there had been "about three phone calls to my electorate office" about his vote on the gay marriage bill.
Helensville local Jools Topp, from lesbian comedy duo the Topp Twins, was not impressed either. "Helensville is a cool town and I have never had a problem there," she said. "We could do without hate-fuelled opinions being thrust into our mailboxes."