The former Dunedin Labour MP told the Otago Daily Times when contacted yesterday he would ask chief executive Brian Roche about zero-hours contracts when the pair met tomorrow.
''I want to talk with the chief executive about that.
''I would be very concerned if we were involved in any kind of permanent arrangement around zero-hour contracts,'' Sir Michael said.
On Monday, the Otago Daily Times published a story about a worker who said on-call staff had to be available all the time, and if not were penalised by losing hours.
New Zealand Post management said it was not using zero-hours contracts, but this is disputed by the Engineering, Printing and Manufacturing Union.
Sir Michael said there was clearly disagreement between the union and New Zealand Post, and usually a chairman kept clear of employment issues.
However, he was ''absolutely'' aware of publicity focused on the fast-food industry, the widespread condemnation prompting that industry to move away from the controversial arrangements.
Sir Michael said he would be comfortable with the casual arrangements if they were only an interim measure while the company restructured for the July delivery cut.
The former St Kilda and Dunedin South MP and Labour Government finance minister said he had to keep his role as chairman separate from his ties with Labour, traditionally a party concerned with workers' rights.
''I have principles, but I have to keep my position as a Labour Party person separate from a position as chair of an SOE under a National Party government.''
EPMU national industry organiser (postal and logistics) Joe Gallagher said he found the management response reported by the ODT this week ''fascinating''.
''If they're not zero-hour contracts, what are they?''
The union pushed for secure work for posties but faced an aggressive cost-cutting programme which included delivery cuts.
''One of the things that does pain me is they want to make people redundant, but they want to have more on-call people, and that's because it's a lower fixed cost for them.
''This is the whole new model. The Government is really the one that opened Pandora's box on this.''
The worker had also said entitlements in their on-call contract were not being honoured, and Mr Gallagher said they should complain to the union and the matter would be rectified.
