Mr Seymour originally indicated he might not oppose a repeal of the SkyCity deal but later changed his mind after pressure from Government.
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• Act leader David Seymour told to keep calm over SkyCity convention centre
Ms Martin said: "Mr Seymour ... will not vote to repeal something that he believes is fundamentally wrong. Totally against his party's principles. Totally against his values. But no, he can't bring himself to stand up for those things."
Mr Seymour said the repeal would leave the Crown holding the bill for a $400 million convention centre and would undermine New Zealand's reputation for regulatory stability.
The 2013 law change which Ms Martin was attempting to repeal awarded the casino giant gambling concessions in exchange for funding a new convention centre in Auckland.
Parliament also voted down bills under the name of Labour MP Phil Goff and New Zealand First MP Fletcher Tabuteau.
Mr Goff's bill would have limited the sales of New Zealand farms to offshore buyers.
The Labour MP said he wanted to end the "rubber-stamping" of farmland sales to foreigners, which had seen the Overseas Investment Office approve all 370 applications over the last three years.
In a debate which mirrored the recent discussion on foreign ownership of homes, Mr Goff angrily rejected claims that the law change would be a racist move.
"There is nothing in my bill that discriminates against any New Zealanders. What it does is acts on behalf of every New Zealander.
"I've talked to my Chinese constituents and my Indian constituents and they think that it's a good idea that New Zealand should own its own future."
Mr Tabuteau's bill would have banned New Zealand from entering international agreements which had provisions for investor-state dispute settlements (ISDS).
He said he was "deeply concerned" that ISDS provisions could be part of the Trans Pacific Partnership (TPP), which could allow corporate firms to directly sue Governments which passed unfavourable legislation.
The Labour Party felt the bill was too broad, but backed it because it wanted a debate about on the issue.
Labour MP Meka Whaitiri's private member's bill passed with support from Labour, Greens, New Zealand First, the Maori Party and United Future.
It made sure that protecting, maintaining and enhancing the environment was explicitly stated as one of the Environmental Protection Authority's goals.
Ms Whaitiri said that when the agency was created, its legislation had a major oversight.
"The Act ... did not actually require the protection of the environment as part of the authority's role. The bill aims to correct that defect."
"What this bill does is place protection of New Zealand's natural environment right at the heart of the law governing the Environment Protection Authority."
She said it was an important change in light of reports that EPA staff were struggling to determine what the mission of the organisation was and who they were accountable to.
"We ... do not want a situation in the future where short-term economic thinking is allowed to impinge on the Environmental Protection Authority's function because the agency's mission is legally unclear."
National and Act opposed the bill.
Environmental Minister Nick Smith said it was a "bad joke" which showed how shallow Labour's policies were.
"Labour seems to think that by repeating the words 'environment' and 'protection' in the law we will somehow magically save the kiwi, address our water quality challenges and eliminate greenhouse gases," he said.
