Up to 600 broadband installation workers subcontracted by Chorus are being urged to sign a new contract that will lower their pay by up to 30 percent, according to E Tu Union.
One subcontractor, who spoke to RNZ Business on condition of anonymity, said signing it would send him out of business.
"[My business] won't be viable on the new contract. They are cutting costs, so they are cutting what we finally get [paid]. How are you expected to make a profit?"
He said the lower coded rates outlined in the 858-page contract he was sent by email late last week would leave him $20,000 out of pocket a year.
Chorus spokesman Nathan Beaumont said its pay rates had not reduced by 30 percent, however, there had been some changes to rates to reflect the reduction of work available on its copper network.
The contract sent by Chorus' contracted firm Visionstream, obtained by RNZ Business, said the new pay rates would apply immediately, despite the contract not coming into force until the end of this month.
It said it would put subcontractors out of work if they did not sign it and they could not speak to media about the contract without gaining Chorus' written approval.
Visionstream renewed its contract with Chorus earlier this year, allowing it to keep hiring third parties, called service companies, to install and maintain broadband lines in Auckland homes.
That was despite Visionstream previously being found to have not supervised service companies who were exploiting workers.
Chorus commissioned an independent review into the issue, and at its release in April, said it would review subcontractor pay.
The subcontractor said the new contract was not what Chorus had promised.
"If these are the recommendations after their investigations, then it is no better. It is worse. Everything they [Chorus] have promised is not being followed through."
He called for Chorus to cut Visionstream out and contract the workers directly.