Firebrand Maori Party MP Hone Harawira is considering a tilt at the party's leadership over the foreshore and seabed legislation, claims Ngapuhi academic and leader David Rankin.

Mr Harawira and co-leaders Tariana Turia and Pita Sharples are not commenting on the claim.

"Over the past several weeks, I have been informed by two people close to the Maori Party hierarchy that Hone Harawira is planning a coup against the party's co-leaders, Tariana Turia and Pita Sharples," Mr Rankin said yesterday.

Mr Harawira did not return Herald calls and a spokeswoman for Mrs Turia and Dr Sharples said they did not wish to comment.

Mr Rankin said Mr Harawira was to challenge his leadership over the Marine and Coastal Area (Takutai Moana) Bill, which replaces the foreshore and seabed legislation and passed its first reading on Wednesday.

While four Maori Party MPs supported it, Mr Harawira did not.

Mr Harawira mocked the bill, saying it would give Osama bin Laden more rights to buy a piece of the foreshore and seabed than he would have.

Mr Harawira said last week that when Dr Sharples and Mrs Turia spoke they represented the interests of the party.

"When I speak I represent the interests of the electorate, I represent the interests of a sector of our community that does not accept this bill."

Mr Rankin said: "Maoridom themselves do want the foreshore and seabed returned to them with total ownership and total control and Hone's preaching this and what's happening is he's getting a massive groundswell of support from the people.

"It is clear that Hone does not have the numbers in the parliamentary party for a successful leadership bid but among the party membership, his support is substantial, and party officials are looking at that support base and wondering whether they can afford to squander it."

But Mr Harawira said last week there was still a genuine desire within the party to stand as one.

"The division isn't there at all. All I'm doing is voting the way all of my colleagues feel and voting the way a lot of Maori people feel about this second piece of legislation.