Prime Minister John Key is rejecting opposition calls for him to sack John Banks.
Labour is piling on the pressure after the police released their file on the donations given to the ACT leader for his 2010 Auckland mayoral campaign, but Mr Key says nothing has changed.
The file includes evidence from internet piracy accused Kim Dotcom that at a meeting in June 2010 Mr Banks asked for a $50,000 donation to be split into $25,000 cheques so he wouldn't have to declare where they came from.
"He said to me `I want to help you Kim and I can help you more effectively if no one knows about this donation'," Mr Dotcom said in an affidavit.
Mr Banks declared the donations as anonymous and police concluded that while that was wrong there wasn't sufficient evidence to prosecute him under electoral law.
The MP holds ministerial portfolios under a support agreement with National and Labour says Mr Key should sack him because it has been proved he didn't tell the truth about the donations.
Mr Key told One News he wasn't going to do that.
"Nothing has changed when it comes to that position. This is a politically-motivated attack," he said.
Mr Key has consistently refused to sack Mr Banks, saying police didn't prosecute the MP.