Labour MP Shane Jones has made fresh claims that Countdown has used extortionary tactics against food suppliers. He says scores of suppliers have contacted him supporting his allegations.
Using parliamentary privilege, Mr Jones first claimed a week ago that the supermarket chain has told firms supplying products and produce to its stores that they need to pay compensation for losses it suffered in 2013.
Speaking again under the protection of parliamentary privilege, Mr Jones on Wednesday accused the chair of Woolworths Australia, which owns Countdown, of ringing suppliers to tell them not to co-operate with a possible Commerce Commission inquiry.
The chairperson, Ralph Waters, has denied the claim.
Mr Jones told Morning Report scores of suppliers have contacted him supporting his allegations with some suggesting the duopoly that controls most of New Zealand's supermarket sector isn't working.
"I'm astounded by the number of people who have suddenly said 'To hell with it, we've had a gutsful of this, we're going to back you, Jonesy'. There are scores of suppliers who have emailed me, who have called me and sent messages of support with very detailed episodes in their dealings with this sector of the economy."
The MP is to meet the Commerce Commission on Thursday. He says he wants to make sure the Commerce Commission can guarantee the anonymity of potential witnesses.