Former Epsom MP Richard Worth has attacked his successor Rodney Hide in an early bid to reclaim the seat, saying Mr Hide's support for "widespread drug legalisation" will horrify the electorate.
Mr Hide is believed to have complained to National leader Don Brash about the claim, sent out in a press statement and alluded to in a letter to Epsom electors.
But the Act leader is being particularly coy about what his stance on the issue actually is.
Announcing his "Epsom Fight Back", Mr Worth said in the release he was committed to winning the seat back and believed Mr Hide had deceptively suggested the electorate would get four or five Act MPs if Mr Hide won the seat.
"Mr Hide's values are not Epsom's values ... Mr Hide supports widespread drug legalisation for example, a stance that will horrify many in Epsom."
The letter is similar but more subtle, yet provides a link to the website of pro-cannabis reform group Norml, which quotes Mr Hide saying in 2003 at an Act event "I would legalise all drugs."
Mr Hide was evasive when asked about the claims.
"I don't know what that's about."
Herald: "Do you support widespread legalisation?"
Mr Hide: "No."
Herald: "What about cannabis law reform?"
Mr Hide: "No, I think he's confusing me with Nandor [Tanczos]."
Herald: "So you don't support cannabis law reform?"
Mr Hide: "Well, it's not been an issue in Parliament."
Herald: "It has in the past ... "
Mr Hide: "It's never come up for a vote in my time there ... I'm not campaigning now for the seat of Epsom. What I'm doing is my best to represent the constituents and my big focus is on crime and transport. I'd just like to work with Richard Worth and the National Party and leave the campaigning to the campaign."
Herald: "What about the Norml website quotes?"
Mr Hide: "I'm just not interested in commenting on his letter."
Herald: "Do you have a view on cannabis law reform?"
Mr Hide: "I don't think the prohibition on cannabis is giving a good result and I'm all for looking at better ways of managing it. I think it's having no impact on the use of cannabis at all and you can easily see that because we can't keep cannabis out of prisons so we certainly can't keep it out of our streets, no matter how many police we have. So I've always been sceptical of our drug policy and always probably will be. But does that mean I go around and advocate legalisation, of course not."
Herald: "Not decriminalisation either?"
Mr Hide: "It hasn't come up for a vote but certainly if it did it would get interesting because I think it's an important debate to have."
Herald: "Are you saying you don't have a view?"
Mr Hide: "No, I'm saying it hasn't come up for a vote."
A National spokesman said Dr Brash did not criticise Mr Worth's material, but distanced himself from it, saying it was a matter for the National electorate branch.
"It's a local membership drive. They are clearly enthusiastic."