Whitehall is full of 'complacency and duplicity' and led by politicians who deliberately withhold information from the public by obstructing the work of journalists, the Leveson Inquiry has heard.
John Kampfner, chief executive of Index on Censorship, which champions freedom of expression, said there is "a determination" in the corridors of power to keep ordinary people in the dark.
The former journalist, who has worked for titles including the Daily Telegraph, the Financial Times and the New Statesman, said there was a "very secretive Whitehall mindset".
He said: "There's a suspicion, invariably, of information and ... there's a determination to keep as much information out of the public domain as possible."
He said parliament had "rolled over" on the issue of superinjunctions, but it did not do enough for freedom of expression.
"The record of Parliament in implementing a force towards better accountability and better transparency is very poor indeed," he said.
Recalling an incident in his time as chief political correspondent for the Financial Times, he said he refused to be "fed stories" by a spin doctor, whom he did not name.
The man said: "Take it down if you want more from where this came in the future."
There was "a culture of complacency and duplicity", he said.
Mr Kampfner was giving evidence alongside Jonathan Heawood, director of English PEN, which campaigns for writers and journalists.
The pair were asked by Robert Jay QC, counsel to the inquiry, about the balance between Article 8 of the European Convention on Human Rights, the right to privacy, and Article 10, the right of expression.
Mr Heawood said: "I think ultimately those are both right.
"This is not simply about one right trumping another."
Mr Kampfner said Index on Censorship believes the right to freedom of expression can outweigh privacy.
"I think I would take a more emphatic position," he said.
"We, as an organisation representing freedom of expression in the UK and around the world, do regard Article 10 rights as fundamental to democracy."
He said there are examples where the right to freedom of expression are necessarily restricted, but his organisation would like public interest defences to be in laws which currently do not have any.
"But where there are competing rights, Article 8 rights, as determined by judges ... will come up against those competing rights, but we do start from a straightforward Article 10 position."
Mr Kampfner warned that "the continental view of privacy, which is pretty much everything is private unless we seek to make it otherwise" is "wrong and dangerous".
Referring to high profile privacy cases involving footballers, he said: "These are difficult issues and there does need to be a public interest, a strong public interest defence.
"We would very much assume a public interest unless there is a convincing argument that there isn't - and certainly the public realm is a public place."