Australian Public Service Commissioner John Lloyd says the federal bureaucracy has a culture of "don't put it in writing" caused by harmful freedom of information laws.
Labor and Greens senators grilled Mr Lloyd about his views that the laws which allow members of the public to access government documents at a Senate estimates hearing on Monday.
Mr Lloyd said he had not approached any government ministers with his views that the laws were "very pernicious" which were reported in March.
Greens senator said Lee Rhiannon said Mr Lloyd's position could send the wrong message to public servants dealing with freedom of information requests.
"When you speak in that way and particularly when you don't follow through with recommendations, can't you see it could be determined there's a bias...and people may become more reticent in this process," Senator Rhiannon said.
"Why has the response stopped with that comment and you haven't followed through on that?"
Mr Lloyd said as public service commissioner he had a responsibility to "at times" comment on matters relating to the administration of the public service.
He said the laws were "less than ideal" and had gone beyond their original intent which aimed to allow members of the public to access personal records.
"It seems to me it's now used for various purposes often involved in the controversy of the day.
"As a senior official over the past 20 years I've been struck by how cautious people are about giving advice in writing because of FoI.
He said the home insulation royal commission had found there was too little written advice found in relation to the government's decision making processes.
Mr Lloyd rejected a claim by Labor senator Joe Ludwig that his opinion had been formed 20 years ago and not updated since.
He also rebuked another claim that his own decisions made about freedom of information requests lodged with his office would be biased because of his views.
He said the law did not allow him to be biased.
In the same hearing Mr Lloyd disputed claims the bureaucracy was experiencing the worst industrial action in a generation made by the Community and Public Sector Union.
When asked whether he agreed with the major public service union portrayal of massive disruption caused by industrial action "I wouldn't think so".
But he conceded half-day strikes by Department of Immigration and Border Protection and Agriculture Department staff at the nation's airports recently had been taken more seriously.
"In the agencies experiencing industrial action less than 30 per cent of employees are union members and eligible to take action," he said.
"In the Department of Human Services which has a high proportion of union membership less than 15 per cent of staff participated.
"In other agencies less than 10 per cent of staff participated."
Liberal senator Cory Bernardi said this did not match up with CPSU national secretary Nadine Flood's statements that the industrial action was widespread and included tens of thousands of staff.
Minister assisting the prime minister on the public service Michaelia Cash said the CPSU was not changing its position of a four per cent per year pay rise over three years even though bureaucrats had received pay rises exceeding inflation in the past decade.