Foreign Affairs Minister Winston Peters is to meet Prime Minister Helen Clark on Tuesday to discuss allegations over his handling of New Zealand First donations.
Miss Clark has had staff going through the allegations and is expected to discuss them with Mr Peters on his return from official duties overseas.
Mr Peters travelled to Samoa on Sunday with United States Secretary of State Condoleezza Rice for a meeting of Pacific Island foreign ministers.
Speaking in Rotorua on Monday, Miss Clark said she is bound to accept Mr Peters' word that there has been no illegality, and will need some persuading that there is not more heat than light on the matter.
Meanwhile, the administrator of the Spencer Trust, Wayne Peters, says he is not worried about businessman Sir Robert Jones' concerns that his donation may not have reached New Zealand First.
Sir Robert says he gave $25,000 to New Zealand First in 2005, through the trust, after Mr Peters, the party's leader, asked him for a donation. He wants to know whether that money was passed on to New Zealand First.
Wayne Peters, who is Mr Peters' brother, says he does not have the slightest concern about Sir Robert's remarks.
He refused to elaborate further, saying he was not prepared to discuss the affairs of the trust.
Allegations 'rubbish' - Peters
On Friday, in a sometimes heated news conference in Auckland, Mr Peters hit out at criticism of his handling of New Zealand First donations, saying the allegations against him were "unsubstantiated rubbish".
He disputed a claim by Sir Robert Jones that he intended a $25,000 donation to go to his party before the last election.
Sir Robert had a cheque written to the Spencer Trust in 2005, after he says Mr Peters asked him to donate to New Zealand First.
Sir Robert says he had previously donated about $150,000 to the party.
However, Mr Peters said he has no involvement with the Spencer Trust.
"Mr Jones has made a number of statements which, in hindsight, he will admit are not factual: One is to the amount; two is to where it went; three is to any idea that it might have got somehow into my pocket - which was the inference that was made by the journalists of this country."
But Sir Robert insists he has not experienced a memory lapse, and says Mr Peters' denials are both silly and sad.
He remains adamant he made a $25,000 donation to New Zealand First three years ago.
At the Friday news conference, Mr Peters said the media had run a campaign of innuendo and misrepresentation. He lashed out at journalists, calling them "reef fish making repugnant allegations without facts".
Mr Peters said party officials told him there is nothing to disclose.
Former Jones employee recalls donation
Malcolm Wright, who worked for Sir Robert three years ago, says he recalls Mr Peters and a staff member visiting Sir Robert for drinks in 2005, where the issue of a donation was discussed.
"Sir Robert was opposed to making a donation. In the end, though, he agreed that he would. There had been a higher sum asked for, and Sir Robert said: 'Well, I'll give you $25,000 for mateship', which Winston agreed to, and they shook hands on that."
Professor Wright says he was told some days later by one of Mr Peters' staff members to make out a cheque to a trust, although he cannot recall its name. He says Sir Robert thought the money was going to New Zealand First.
However, there is no record of the donation in New Zealand First's 2005 or 2006 donation returns.
Mr Peters also faces allegations over a $100,000 donation towards his legal costs from businessman Owen Glenn, 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.
ACT leader wants answers
ACT Party leader Rodney Hide has written to the Cabinet secretary asking her to clarify the obligations of the minister of foreign affairs. He has also asked the Cabinet secretary about declarations Mr Peters has made on the Register of Pecuniary Interests and any conflicts of interest that might have been identified.
Last week, Mr Hide complained to Parliament's Speaker, Margaret Wilson, about Mr Peters' failure to declare a donation from Mr Glenn and has asked Miss Clark to investigate all the allegations involving Mr Peters.
Mr Peters says New Zealand First has always played by the rules and will take legal action against The Dominion Post over suggestions some donations to the party may not have ended up in its accounts.
