Glenn will return to New Zealand to give evidence in person to Parliament's privileges committee - setting up a showdown withPeters.
The committee announced this morning it would hear evidence from Mr Glenn next Tuesday as it probes conflicting accounts of his $100,000 donation to Mr Peters.
An explosive letter from Mr Glenn last week contradicted the NZ First leader's denials that he found out about the 2005 donation only in July.
The announcement was made by privileges committee chairman Simon Power within minutes of Mr Peters arriving to give further evidence to the committee.
Mr Peters arrived with his lawyer Peter Williams QC, who delivered a statement to the committee.
But there were tense scenes over Mr Williams' testimony, after it was repeatedly ruled as straying outside the scope under which he had been allowed to appear.
Mr Power warned at one stage that Mr Williams was on his final warning.
But Mr Williams warned that his evidence was "fundamental to fairness and democracy and the rule of law". It would be a "sad day for democracy" if it was "suffocated" by the committee.
Mr Peters remained silent throughout his lawyer's testimony, which also questioned the fairness of the proceedings.
The hearing was over by 9.15am.
Immediately after the hearing, the committee released a new letter from Mr Glenn, in which he stood by his earlier evidence that the $100,000 donation was made him in response to a personal request from Mr Peters. Mr Peters said it was his lawyer, Brian Henry, who requested the money.
In his letter, Mr Glenn said he had an email from Mr Henry in which Mr Henry referrs to an earlier conversation "between me and a person Mr Henry refers to as 'my client'."
"There is absolutely no doubt that the request came to me from Mr Peters," Mr Glenn's letter stated.
In his earlier letter, Mr Glenn said he made the donation at Mr Peters' request after the NZ First leader sought help in a personal conversation.
"I agreed to help in the belief that this step would also assist the Labour Party, in its relationship with Mr Peters. I supported the Labour Party," his letter said.
Mr Peters continues to insist that he knew nothing about the donation till he was informed by his lawyer, Brian Henry, and has said he will front up to the committee with evidence.
The NZ First leader pulled out of a top level business conference yesterday as he came under pressure on two fronts - his insistence that he had no knowledge of the Glenn donation when it was made, and a Serious Fraud Office investigation into NZ First party finances, after donations were channelled into the previously unknown Spencer Trust and never declared.
Mr Peters was forced to stand down from his ministerial portfolios on Friday till the investigation is complete.
The privileges committee sought evidence from Mr Glenn at the start of its inquiry but had no power to compel the Monaco-based businessman and philanthropist to appear. However, he had promised to cooperate fully.
The committee also has to decide whether it will call Miss Clark, who has confirmed that Mr Glenn told her in February about the donation.