Government members of Parliament's commerce committee have blocked a request to have Progressive Enterprises to appear before the committee after receiving a legal letter from the supermarket chain.
Progressive Enterprises, which owns and operates more than 165 Countdown supermarkets in New Zealand, is already facing allegations of anti-competitive behaviour.
Labour Party MP Clayton Cosgrove, the committee's acting chairperson, describes the letter as at best menacing, and at worst intimidatory.
It asks for a copy of information from a hearing two weeks ago when MPs asked the Commerce Commission about its investigation into allegations of anti-competitive behaviour by Progressive's Countdown chain.
The committee held an urgent closed meeting on Tuesday afternoon, when members voted to release the letter but blocked a request by Mr Cosgrove to call the company before it to discuss the matter.
Mr Cosgrove said he was hugely disappointed Government MPs on the committee had rejected his request to have Progressive Enterprises appear before it.
"I find this very, very strange and disturbing, given that it is rare, where natural justice issues are raised by individuals or entities," he said.
"In my view, they should be given their day in the sun and invited to come in and appear before the committee and raise any issues they have."
But National Party MP Chris Tremain, who sits on the committee, said it was a straightforward decision.
"We've released what is important to be in the public domain... There was no need to go any further than that and provide a political stage for Mr Cosgrove."
Progressives earlier issued a written statement saying it was wrong to suggest the letter was threatening. It said it had simply made a logical and rational request under standing order 232 to find out what was said at the select committee meeting, rather than relying on news media reports.