Labour Party leader Phil Goff has accused the Government of trying to buy time in the way it is handling Pansy Wong's absence from Parliament.
This will be Ms Wong's second week of leave after her resignation from her Cabinet posts for misusing her international travel subsidy.
Mr Goff says there is no excuse for her not being in Parliament this week to answer questions.
But Prime Minister John Key says Ms Wong is justified in being on leave until an inquiry into her use of the international travel subsidy has been completed.
Mr Key says the absence is justified because she does not yet have all the information needed to answer questions from the media.
A Parliamentary Service investigation into her use of her taxpayer-subsidised travel discount is under way.
Mr Key supports Ms Wong staying on as an MP despite continuing calls from Labour for her to resign.
Asked why she has been given another week's leave from her parliamentary duties in Wellington, Mr Key said Ms Wong was not yet ready to face the media.
He says he wants Ms Wong to be able to answer any questions directly and with the full facts in front of her - something she can not do until she reads the Parliamentary Service report.
Mr Goff says Ms Wong should resign from Parliament or, if she won't, Mr Key should have her removed her from the National Party caucus.
However, Mr Key says there is no reason for Ms Wong to resign as an MP.