Prime Minister John Key has indicated he has little sympathy for Peter Dunne's concerns that information about his emails was accessed without his permission during the inquiry into the leak of a sensitive GCSB report.
Mr Dunne resigned from his portfolios after refusing to release the content of emails between himself and journalist Andrea Vance just before Ms Vance reported on the contents of the so-called Kitteridge report which revealed potentially illegal spying by the GCSB.
It has emerged that former public servant David Henry who conducted the inquiry asked Mr Dunne for the emails after examining "metadata" or logs of Mr Dunne's email traffic.
Mr Dunne said he never gave his permission for this data to be examined.
Mr Key said he had some sympathy for concerns journalists such as Ms Vance may have about their metadata including information about their movements around the parliamentary complex being examined without their permission.
That did not extend to Mr Dunne.
"I have very limited sympathy if any at all for a minister or former minister, and the reason for that is when you're a minister you swear an oath of allegiance and that oath basically says that you'll treat information confidentially.
"By definition if you have nothing to worry about then access to metadata is part of a proper and full inquiry and should be of no concern to anyone."
Mr Key said his office made it clear when it initiated the inquiry into the leak that he expected ministers to co-operate.
"The terms and conditions were spelled out absolutely in plain English what was going to happen and what information was going to be looked at and that included email traffic."
Mr Dunne last night said he understood other ministers received a letter from those conducting the inquiry seeking approval to access their email logs, "but the letter was not sent to me".
"I think that was an oversight but the fact remains that to access the metadata without approval of the ministers concerned was a breach of the protocol the Department of Prime Minister and Cabinet [DPMC] itself had set up."
Mr Dunne did not believe that when ministers were sworn in they surrendered their right to privacy.
"I first became a minister 23 years ago ... At no point ever has anyone suggested to me that the executive councillors' oath gives carte blanche access to your email traffic."