Key Points:

Monaco-based businessman Owen Glenn says he has come back to New Zealand to clear his name and whatever might happen to Winston Peters as a consequence is not up to him.

Mr Glenn will appear before the privileges committee at Parliament late this afternoon to give evidence on the $100,000 donation he made in 2005 towards Mr Peters' legal fees.

The billionaire said he had brought two staff members with him and they would be at the hearing today. He would make a statement to the committee and then be available to be questioned.

"I'm just here to clear my name, that's all," Mr Glenn told the Herald yesterday. "I just want to get rid of it and get on with my life."

Mr Glenn said he had brought some corroborative evidence - "such as we can looking back over three years, as much as we could establish".

Mr Peters' future may depend on what comes out of the hearing. He's assured the public and Prime Minister Helen Clark that he learned of the donation only in July, and has repeated that to the privileges committee.

Mr Glenn has testified in two letters to the committee that Mr Peters personally asked him for the donation, which was given in December 2005, and then thanked him for it at the Karaka sales in 2006.

Mr Glenn disputes the testimony of Mr Peters' lawyer Brian Henry, who said it was he, Mr Henry, who solicited the donation for the cost of the Tauranga electoral petition on the suggestion of a client whom he won't name.

"There is absolutely no doubt that the request came to me from Mr Peters," Mr Glenn's most recent letter said. "I would not have made the donation on any other basis through any intermediary. I did not do so."

Asked yesterday if he was aware Mr Peters could be sacked if he were proven to have misled the Prime Minister, Mr Glenn said: "It is not up to me to decide. I think what everybody forgets here, I made a donation. I did everything correct."

He said it was up to the people receiving donations to act accordingly. "I'm not responsible for their actions."

Mr Glenn said he'd had no idea about the procedures and regulations surrounding such political donations.

"I didn't do it for any other reason than good faith.

"Sometimes I wonder if it is worth it all. It certainly hasn't proved to be in this case. I've followed all the right procedures and [today] is D-Day."

Helen Clark said yesterday it was still entirely possible there was an "innocent explanation" for the conflicting evidence.

"Something has to provide an explanation for what happened and everyone is very reluctant to draw the conclusion that lies have been told about it," she said on Breakfast.

"The issue is for the privileges committee to sort out."

Mr Glenn said yesterday afternoon he was not expecting to meet Mr Peters during his visit to New Zealand and that he was unaware any request had been made by him for a meeting.

Mr Glenn said he had been hounded over the issue.

"I don't want to say anything more now. I might just write a book."

Mr Henry is overseas and had been due back in New Zealand this week. However, it is believed his return has been delayed.

The privileges committee's job is quite a narrow one - to determine whether Mr Glenn's donation was a gift and should therefore have been declared in the register of pecuniary interests.

Owen Glenn vs Winston Peters:

Owen Glenn will appear before the privileges committee tonight.

Winston Peters will appear before the committee tomorrow night.

What is at stake?

Mr Peters' credibility, his job as a minister and NZ First's survival.

What is in dispute?

Mr Peters says his lawyer, Brian Henry, asked for a $100,000 donation to fund legal fees for the Tauranga electoral petition. Mr Glenn says Mr Peters asked for it.

Why does it matter?

Mr Peters told the public and the Prime Minister he found out about the donation only on July 18 this year. If he asked for it, he has lied.

What does Helen Clark say?

Mr Glenn and Mr Peters are both honourable men and she hopes there is an "innocent explanation" for their differing accounts.

Is there a possible innocent explanation?

Mr Peters might argue that Mr Glenn was simply confused about who he had spoken to about the donation and that he mixed up Mr Peters and Mr Henry.

What is the evidence?

Mr Henry has filed supplementary testimony as to what was discussed in the alleged conversation with Mr Glenn: Alexander Downer (the Australian Foreign Minister at the time) and the stability of the NZ Government.

Mr Glenn has brought material and staff that may corroborate his version.

Known meetings between them:

2005 Sydney, both there for the Bledisloe Cup; 2006 Karaka, yearling sales; 2007 Paris, both there for the Rugby World Cup.