Prime Minister Helen Clark on Wednesday faced a second day of questioning in Parliament over donations received by Foreign Affairs Minister Winston Peters.
National continues to question why Miss Clark has not taken any action against Mr Peters, but Miss Clark says any inquiries are up to the likes of the Registrar of Pecuniary Interests.
She told Parliament that even if the donation to Mr Peters' legal bills were found to be a gift, there would be no reason for him to relinquish it.
New Zealand First MPs defended their leader in Parliament against suggestions of corrupt practice.
The Greens put questions to Miss Clark about whether any donations have influenced decisions Mr Peters has made in his capacity of racing minister.
The question drew a spirited response from New Zealand First MP Ron Mark.
National says the allegations about Mr Peters are serious, and Miss Clark needs to get to the bottom of them.
The row centres on a donation of $100,000 towards Mr Peters' legal costs as well as a report in The Dominion Post newspaper that his party received up to $150,000 from a prominent racing-industry family between 1999 and 2003.
Mr Peters says New Zealand First has always played by the rules and he will take legal action against The Dominion Post over suggestions some donations to the party may not have ended up in its accounts.
National leader John Key says Mr Peters misled the public over the $100,000 donation from businessman Owen Glenn in 2006 to help pay the costs of an electoral petition. The donation was confirmed by Mr Peters on Friday.
A Radio New Zealand political reporter says Mr Key will not rule out working with Mr Peters if National leads the next Government, but says he will expect transparency over donations from all ministers.
