Key Points:

New Zealand First leader Winston Peters will give further evidence to the privileges committee today in what is thought to be a response to evidence offered to the committee by the Serious Fraud Office.

Mr Peters is scheduled to be heard in private but a spokesman for him last night confirmed he had been asked to be heard in public.

The committee is scheduled to meet for two hours this afternoon and there are no public sessions scheduled.

So if Mr Peters has been asked to appear in private, the SFO is likely to have been asked to be heard in private or have requested to do so.

The privileges committee and the SFO are both conducting inquiries around issues related to New Zealand First donations, but until now there has been no apparent cross-over. Mr Peters has been stood down as Foreign Minister while the SFO conducts its investigation.

The SFO inquiry has been centred around the Spencer Trust, which has been a secret source of funding for undeclared donations for the party.

The Spencer Trust was mentioned briefly in the privileges committee's first public hearing on August 18 when Mr Peters' lawyer, Brian Henry, told the committee, "I have nothing to do with the Spencer Trust".

Mr Henry was not sure if any of his bills had been paid by the Spencer Trust.

The privileges committee inquiry is centred around a $100,000 donation from billionaire Owen Glenn to pay for Mr Peters' legal fees for the Tauranga electoral petition in 2005.

Mr Glenn provided phone and email records to support his claim that Mr Peters had sought the money.

Mr Henry's second appearance on Tuesday did nothing to undermine Mr Glenn's version of events, and calls for Mr Peters' sacking as a minister altogether were stepped up.

However Prime Minister Helen Clark said the strong advice she had received from Cabinet ministers Michael Cullen and Lianne Dalziel on the committee was to let the process continue.

"They say the conflict of evidence is there as it has been all the way through."

Helen Clark said on Monday that unless there was a "devastating development" at the committee on Tuesday she would wait until the panel tabled its report - probably next Monday - before deciding what to do.

Yesterday, she hinted she might suspend her own judgment until the SFO reports.

"I'm waiting to hear from the privileges committee but I'm also waiting to hear from the Serious Fraud Office.

"Remember what prompted the standing aside of Mr Peters from all his portfolio work. It was the Serious Fraud Office starting its investigations."