A government minister has apologised to senior colleagues after appearing to threaten political opponents if they criticise National's policies.

Photo: National Party

At the National Party's Auckland conference yesterday Alfred Ngaro warned Labour list candidate Willie Jackson of the financial consequences for the Manukau Urban Māori Authority if Mr Jackson bagged the government on the campaign trail.

Willie Jackson heads the Māori urban authority which has runs a charter school and a Whānau Ora contract.

Alfred Ngaro, who's the associate minister of social housing, told the National conference Mr Jackson could lose the contract and also support for a second charter school if he criticised the government.

The finance minister, Steven Joyce, said Mr Ngaro, had apologised to him, the prime minister and the deputy prime minister and Mr Jackson's charter school wasn't under threat.

"It's not the way the government operates, we work with providers of all types in terms of working relationships and they all have different politics and their politics doesn't get involved with the way that the government contracts and nor should it," said Mr Joyce.

The Labour Party leader, Andrew Little, said Mr Jackson had now stepped back from his private interests to focus on his candidacy.

He said Mr Ngaro's comments were out of order and New Zealanders deserved better.

In a statement, Mr Ngaro said his remarks were a bit naive, poorly worded and he regrets them.