The Labour Party is yet to decide whether it will back a law change which would allow people to swear an oath to the Treaty of Waitangi.
The private member's bill, sponsored by Maori MP Te Ururoa Flavell, was expected to be debated in Parliament tomorrow.
The legislation was set to fail, with the National Party and New Zealand First confirming they would oppose it at the first hurdle. National whip Michael Woodhouse said his party had seriously and respectfully considered the bill, but had "deemed it unnecessary".
New Zealand First leader Winston Peters previously said the bill was a "separatist" proposal which he could not support.
Labour had not yet decided whether it would support the legislation, and would discuss it in caucus this morning.