E tu union says customer complaints about shoddy workmanship on Chorus' ultra-fast broadband network vindicate quality concerns the union raised months ago.
The Herald has this week published a number of complaints of substandard fibre-optic installations and customers concerned their upgrade will not stand the test of time.
A homeowner from East Auckland told E tu he and his neighbours were worried that their fibre connections will fail.
Residents have reported exposed cables left open to damage by lawn-mowers, dogs and vandals, as well as the use of duct tape to connect cables from the street to their properties.
E tu communications industry coordinator Joe Gallagher said the problems reflect concerns the union raised in April when Downer lost its installation contract with Chorus.
He said the union had warned then that network standards would deteriorate as Chorus chose to use owner-operator sub-contractors. The result is big costs to fix shoddy workmanship after a slew of complaints.
"It's an ultra-shoddy network and we've been saying that for some time, but no one wanted to listen. Now it's become all too apparent that there are quality issues."
Chorus spokesman Nathan Beaumont said: "We do about 600 installs a day and we receive about 10 queries a day regarding installations. As soon as we are made aware of an issue with an installation we will act immediately to put it right."
Mr Beaumont said unhappy customers should call 0800 600 100.