Labour MP Su'a William Sio will vote against the same-sex marriage bill, which he says could cost the party the next election.
The MP for Mangere says there's widespread opposition to the bill in his electorate, which has the highest population of Pacific Islanders in New Zealand, making up 58.8 per cent of voters.
Labour's Manurewa MP Louisa Wall had her member's bill on gay marriage pulled from the ballot and it is expected to pass its first reading when it comes before Parliament next month.
It will be a conscience vote and MPs are already being lobbied on the issue by their constituents.
Mr Sio says some ministers in Pacific churches are preaching against the bill and against Labour.
"This issue cuts deep into fundamental beliefs," he told Radio New Zealand. "It will divide the community."
Mr Sio says the bill is causing unnecessary harm to Labour and should be withdrawn.
"There are more weightier and more pressing issues like holding (Prime Minister) John Key to account for the weakening economy and lack of jobs.
"That's where our priority ought to be, rather than an issue that has the potential to really derail our focus on winning election 2014."
The gay marriage bill could cost Labour more support than the estimated 30,000 votes it lost in the 2008 election over prostitution law reform, civil unions and anti-smacking laws, he says.
But Ms Wall has rejected claims that opposition to the bill from crucial but conservative South Auckland Pacific Island voters could cost the party the next election.
Many Pacific Islanders also live in Ms Wall's electorate but she says she is not getting any resistance from voters.
She had written to all religious leaders, not only Pacific leaders, in her electorate explaining what the bill is about and stressing they would not be forced to perform any gay marriages.
"What I am really worried about is misinformation and propaganda."
Ms Wall says she "completely disagreed" her bill could cost Labour the next election.
Having the Pacific community support Labour's bill is important, she says.
- © Fairfax NZ News
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