Mr Key told TVNZ's Q+A programme today that he was committed to restoring public confidence in the Government Communications Security Bureau following the early release last week of a damning independent review of the spy agency.
He rejected calls for the GCSB to be ditched because "we need to make sure that for national security reasons this organisations operates".
Mr Key, who says new legislation and other operational changes will result from the review, hit out at the "very, very highly critical claims being made [and] personally directed at me" in connection to issues with the GCSB.
Mr Key claimed there was unbalanced reporting by some media covering Ian Fletcher's appointment as head of the GCSB.
Opposition parties criticised the Prime Minister who was revealed to have urged Mr Fletcher, a childhood friend, to apply for the top job.
Mr Key told Q+A the fact that the State Services Commissioner had publicly supported his role in Mr Fletcher's appointment had not been properly reported by some media.
"My reputation matters to me because I am honest and I am up front," Mr Key said.
"And I am also way more accessible than virtually any other leader in the world."
Mr Key said speculation that he would be replaced as the National Party leader before the next election was untrue.
He said he was "actually enjoying" the job.
"As Prime Minister, what are they going to remember when they look back? The answer is going to be is the economy stronger, does the education system work better, does the health system work better, is New Zealand a stronger, more confident country," Mr Key said.
"I've been Prime Minister for four and a-half years, my own personal view is that we are building that sort of New Zealand.
"Is there perfection? There'll never be perfection in politics but you can do your very best."
He said he would National to the next election "because I don't think we've actually finished the job yet".