David Seymour says calls to investigate Hobson's Pledge shows hate speech legislation is "now being used as a political weapon".

The New Zealand Māori Council has asked the Human Rights Commission to investigate the group, led by former ACT and National leader Don Brash, because "no one's called them out".

"They may wear suits and drive around in late-model expensive European cars… but they are nothing more than a gang of misfits that seek to incite hate and divide the country," executive director Matthew Tukaki told Stuff on Wednesday.

"They're creating an environment... in which hate is breeding and not just breeding but duplicating and replicating."

Hobson's Pledge campaigns against what it says is bias and favouritism towards Māori.

"The idea that all New Zealanders should be treated equally before the law is a genuinely-held political view," said Seymour, present leader of ACT and its only MP. "There is nothing inherently racist or violent about it.

"What the New Zealand Māori Council is proposing is that the Human Rights Commission be asked to endorse these kinds of attacks by applying state power to the respondent. Hate speech legislation is now being used as a political weapon."