Helen Clark reckons political polling's behind disagreements in the coalition.

Winston Peters' office released emails showing Prime Minister Chris Luxon was advised against supporting the US and Israel's strikes on Iran.

National's Nicola Willis believes Peters is playing politics - and should have informed them before releasing the emails.

Willis separately accused NZ First of race-baiting in their opposition to the India free trade deal.

Clark says Willis is not holding back.

"New Zealand First is eating fairly deeply into National's support, and that is starting, I think, to become somewhat more corrosive in the coalition." 

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