"In particular, we're concerned about the impacts on superannuitants and low-income families who rely on this annual payment for budgeting purposes," Hawksworth said.
He did not understand why the trustees were proposing such a "dramatic, irreversible change" which made "no sense".
"At the moment trustees are proposing a single option for radical change, which is strongly incentivised," Hawksworth said.
"Whereas we think our local electricity customers deserve to better understand why the change is needed, and to choose from a wider range of options."
Hawksworth said other options could include shifting a greater proportion of funds toward charitable distribution.
"Some of our customers will be implacably opposed and will want to protect the cheque, others will see merit in rebalancing the distribution between customers and community," he said.
"This is very important because customers are being asked to sign away their rights to annual TECT cheques for the next 55 years, which represents tens of thousands of dollars and is a very big decision to make."
Hawksworth said Trustpower will actively participate in the consultation process, including undertaking research with its customers to better understand their perspectives.
"We're very keen to hear people's views on the issue and what they think should happen to the TECT cheque, and how Trustpower can best support them in ensuring their voices are heard," he said.
"It is vitally important any final decision made by the trustees, following the proposed vote by beneficiaries of the Trust, is informed with a full understanding of the facts and the concerns people have with the option the trustees are proposing."