New Zealand Post is denying a claim it deliberately delays mail deliveries in order to promote its premium fast post service.
Postal Workers Union president John Maynard said mail which could be delivered the next day was being held back a day to promote the fast post service.
"We do know that the company is holding mail. We know that mail that is being processed and ready for delivery is being held in the mail centres until the two- to three-day promise that the company has given for delivery of its mail,'' he told Radio New Zealand today.
The delaying tactic had been used for the past three months, upsetting staff, Mr Maynard said.
"They're very upset about it.'
'It's having quite a negative effect on morale and it also demonstrates the clash of culture at New Zealand Post'
"You have a very strong public service, community service culture amongst the postal workers, but increasingly we have a culture of a commercial, profit-driven corporation.''
Not only was mail being held back, but extra staff were not being brought in to process large volumes of mail, Mr Maynard said.
"We know that of the hand-addressed mail, something like 10 per cent of it is falling outside of the company's own delivery promise. This is pretty serious stuff.''
Some fast post mail was also taking longer than it should to be delivered, he said.
"There are occasions where it's taking two days.''
"There is a deliberate policy, we know because we've had a truck driver complain that when he went to pick up mail from a mail centre, it was ready to go, he said 'my truck's half empty, I'll take that mail and he was told 'you can't take that mail, its not to go yet'.''
However, NZ Post's postal delivery general manager Matthew Riordan told RNZ no policy of holding mail existed.
"We don't actually have a policy for holding back mail, when it is ready for delivery it is released"
"We do have a clear differentiation between what we call our standard product and our premium product. Our standard product has a three-day service standard versus the premium which is a next day service.
"When we do process mail we process our priority mail first, knowing that it has to be out the next day and we have a scheduling system for standard post which we have three days to get out to our customers.''
Last month, 96.2 per cent of all mail arrived on time, Mr Riordan said.