Wong should be sacked from National's caucus - Goff

Prime Minister John Key should stop protecting former minister Pansy Wong and sack her after she misused MPs travel perks, Labour leader Phil Goff says.

Mrs Wong resigned her ministerial portfolios after admitting her husband Sammy conducted personal business during a trip to China, which is against the rules covering the use of the rebate for MPs and their spouses.

Speaker Lockwood Smith's office was investigating and a report was expected within three weeks. Mr Key has said Mrs Wong shouldn't comment until she had read the report.

Mr Goff today put pressure on Mr Key, saying he should make Mrs Wong front-up and explain, or sack her from National's caucus.

"This is an outrage," he said.

"She is aware of when she broke the rules and how often she broke the rules. It doesn't need a speaker's inquiry to confirm that."

"The evidence is there. John Key as much as admitted that, saying that he could not be assured that this was an isolated event. He knows the score. She knows the score. They are both covering up and they are playing for time."

Mr Goff said Mr Key promised high standards, and he was not delivering.

"He has done nothing, but make excuses for her, and he has done nothing but try to protect her."

Mr Goff said he made Chris Carter front-up when he racked-up thousands in parliamentary spending, and Mr Key should do the same.

"I just remember the constant attention that was given to Chris Carter. No excuses for Carter. I never made any. Excuses are being made for Wong," he said.

"Other MPs have been prosecuted criminally for doing what she has done. She is still there as an MP, she ought not to be."

When asked about leniency for former Labour Minister Taito Phillip Field, who is in jail for misusing his position, Mr Goff said that case needed to be determined in court.

"He was prosecuted. He was booted out of the Labour Party and I say there is enough evidence that the same should happen to Pansy Wong."

Mr Key said it was an enormous call to throw someone out of caucus.

"Nothing I have heard in terms of the allegations would drive me to believe that she shouldn't be a member of the caucus."

Mr Key said Mrs Wong had not fronted media yet because they want to make sure she can give the public the answers they deserve.

He denied claims that he was delaying the process to avoid a by-election.

"We are not far away from getting that report," he said.

"And when it comes, you'll read it, the public will read it and she'll need to answer those questions.

"If Parliamentary Services thinks there is any behaviour that needs to be accounted for, they should investigate."