Hurricanes coach Mark Hammett has slammed the Bulls' rolling mauls ahead of their match in Napier on Saturday.

Hammett has grown frustrated by the Bulls' tactic, which resulted in a try and a penalty try against the Chiefs last weekend, but admits a change in the laws is highly unlikely.

'The rolling maul is completely illegal in terms of how it's set up,' Hammett told stuff.co.nz. 'I've talked to refs numerous times and numerous other coaches have done that as well, but it's something at the moment they [the referees] aren't prepared to change.

'The biggest issue isn't around the maul, it's the entry of players coming in, in front of the ball carrier and it's done continuously. I don't think it's something that will change mid-season, if at all.'

And though the Hurricane's boss has seen how effective a maul can prove, he says his team can halt the Bulls in their tracks in Napier with the right defensive approach.

'You have to stop it at the source,' he added. 'Whether it's getting up in the air or stopping it before the train gets moving.'