Helen Clark revealed last week that she knew about Owen Glenn's donation to Winston Peters. Photo / Mark Mitchell

Helen Clark revealed last week that she knew about Owen Glenn's donation to Winston Peters. Photo / Mark Mitchell

Prime Minister Helen Clark could be called to appear before Parliament's privileges committee to discuss what she knew about a $100,000 donation to suspended Foreign Minister Winston Peters by expatriate billionaire Owen Glenn.

In what would be an extremely rare occurrence, Helen Clark may be asked about her conversation with Mr Glenn in February, and subsequent discussions with Mr Peters in which he assured her there was no such donation.

The potentially extraordinary appearance would come as the ongoing Peters political donation story takes centre-stage in Parliament this week.

National is set to put Helen Clark under pressure over her revelation last Thursday that Mr Glenn told her as long ago as February that he had given money to Mr Peters.

She checked it with Mr Peters at the time but did not say anything publicly about Mr Glenn's differing view until asked directly.

The Prime Minister's statement threatens to engulf her Government in a scandal perilously close to the election, which must be held within 76 days.

It is not yet clear if the privileges committee will ask Helen Clark for more information. There are 13 members on the committee and a majority would need to back the move.

National leader John Key last night said the committee should call Helen Clark - and the Prime Minister had a duty to appear.

"Her admission last week that she had been briefed by Owen Glenn means that she can make a valuable contribution to the committee in resolving who is right and who is wrong," Mr Key said.

The privileges committee is grappling with conflicting statements by Mr Peters and Mr Glenn over the $100,000 donation.

Mr Peters is reappearing on Thursday.

The privileges committee is working against the clock to complete its report and findings before Parliament rises - possibly on Tuesday or Wednesday next week.

Cabinet minister Trevor Mallard, who was at the private meeting in February where Mr Glenn told Helen Clark about the donation, says the post of honorary consul-general to Monaco was also raised but there had been no suggestion he would get it.

"I have got a vague memory of it being discussed," Mr Mallard told the Herald. "There was certainly no suggestion that it would proceed."

He did not get the impression that Mr Glenn had linked the donation to Mr Peters with the Monaco position. "Not at all."