Thomas said as he understands it, a Goff-led Auckland Council could propose to establish Maori wards under the Local Electoral Act 2001.
"If Goff was serious about his commitment to Maori seats he could propose this next year.
"He talks a big game supporting Maori seats, but when I pushed him at a recent mayoral debate he blamed the lack of Government support as the reason they won't happen.
"That's not true. Although he may be unaware, the Mayor of Auckland can propose Maori wards.
"Goff claims a poll would be too expensive to justify, but a poll is only required if 5 per cent of Auckland electors demand that," Thomas said.
A spokeswoman for Goff said he was not prepared to put Auckland through a costly referendum and the issue was not a priority.
"This is something the Government put out in legislation and the onus is on them to change it," the spokeswoman said.
Thomas suspected the reason Goff will not advance Maori seats in Auckland is that he is afraid it will not be supported.
"Aucklanders may need to get used to this style of leadership if Goff wins the mayoral election in two weeks where he promises one thing but fails to deliver it and blames the Government," said Thomas, who announced last week he was stepping back from his mayoral bid to focus on pointing out the consequences of a Goff mayoralty.