The Prime Minister is not going to force one of his Cabinet Ministers to apologise to Willie Jackson.

Alfred Ngaro made comments about Mr Jackson at a National Party conference over the weekend.

He told delegates that if the Labour candidate criticises the Government, he could lose support for charter school or Whanau Ora contracts.

The Minister has apologised to his own party, but Willie Jackson said he wants an apology too.

He also wants a guarantee personal politics won't colour the way Government delivers its contracts.

Bill English said Mr Ngaro knows he was wrong and has apologised enough.

"I don't think he has to apologise to everyone who didn't like his comment."

Meanwhile, Mr Ngaro's activities as a minister are to be looked into as a result of his comments.

The Prime Minister says he's asked the Department of Prime Minister and Cabinet to take a look.

However, Mr English said it's not an audit.

He said the advice he's had is that Mr Ngaro hasn't been involved in any decisions about any contracts, and for some - such as partnership schools - he certainly wouldn't be.