Act MP Rodney Hide is calling for the Serious Fraud Office to widen its inquiry into New Zealand First's finances to cover all political donations received by the party in the past 15 years.
The Epsom MP said with a question mark over payments made by Sir Robert Jones and the Vela family, it was timely for the party to open its books up to scrutiny.
Hide's call coincides with an apparently "cordial" meeting between Peters' lawyer, high-profile QC Peter Williams, and senior SFO executive Gib Beattie, in Auckland yesterday.
Williams said the documentation provided to the SFO ran to several pages and showed cheques from the Vela brothers and Sir Robert Jones, which were payable to the Spencer Trust were then transferred into NZ First accounts and used for the purposes donors intended.
"I am confident Mr Peters will be cleared very quickly over these matters," Williams told the Herald on Sunday last night.
However, in the face of those assurances the question still remains why SFO director Grant Liddell believed that there was sufficient information to suggest "serious and complex fraud" by NZ First.
The allegations have been considered serious enough for Prime Minister Helen Clark and Peters to agree for him to stand down from his ministerial responsibilities pending the outcome of the SFO inquiry.
How long that investigation will take is still not clear, but given the seriousness and potential complexity of the issues involved, it is unlikely Peters will return to the Cabinet table in the next few days.
The major concern for Peters now is that the longer this matter drags on the more his credibility and the credibility of the party is compromised.
Peters wasn't talking yesterday but Williams again went on the attack, claiming that his client was the victim of an orchestrated witch-hunt led by the likes of Hide, National leader John Key and selected members of the news media.
Yesterday Hide wasn't letting up on Peters, saying it was time the NZ First leader "put up or shut up".
If he could resolve the myriad issues around donations to NZ First in "just five minutes" then why wouldn't he go public with the documentation that would clear his name, Hide said.
"The Serious Fraud Office don't flippantly engage in an investigation against a minister of the Crown a couple of months out from an election."
Meanwhile, Parliament's privileges committee has invited Peters, lawyer Brian Henry and expatriate businessman Owen Glenn to give more evidence next week.
The committee is considering whether Peters should have declared a $100,000 donation from Glenn towards legal bills in 2005.
Helen Clark is being urged by former Labour Prime Minister Mike Moore to announce a November election date in an effort to take some of the political spotlight off Winston Peters.
Labour will announce its party list at noon today but there still appears to be no sign of when Clark will decide to go to the polls.