Newspapers and broadcasters must behave more responsibly in their use of the Freedom of Information Act, according to Lord Chancellor Lord Falconer.
Lord Falconer said people not press were the priority
He said "fishing expeditions" by journalists were jeopardising bodies' ability to deal with public inquiries.
He added the act provided a "right to know" not a "right to tell".
But his comments, made in a speech, were attacked by campaigners for open government and newspaper editors, who denied making "frivolous" inquiries.
The Freedom of Information Act, which came into effect two years ago, gives people the right of access to information held by over 100,000 public authorities.
It has been used by journalists to uncover a range of information, including how many police officers have criminal records and details of MPs' travel expenses.
In delivering the Lord Williams of Mostyn memorial lecture, Lord Falconer said the government had brought in the law "for the people" and not "for journalism".
Freedom of Information Act
72,000 requests for information received by Whitehall since act came into force in Jan 2005
Public Bodies in England, Wales and Northern Ireland must respond to requests within 20 days
Journalists' inquiries amount to 16% of the bill for central government responding to requests under the act
"The job of the government is not to provide page leads for the papers, but information for the citizen," he said.
His speech drew an immediate attack from the Campaign for the Freedom of Information which had lobbied for the change in the law provided by the act.
It accused the government of having a "bunker mentality".
Campaign director Maurice Frankel said: "This is evidence of sensitivity among ministers. They may be right that the press is out to get them, but that is the nature of our democracy."
The speech came just days after Information Commissioner Richard Thomas told MPs that the act was working well.
He questioned the wisdom of government plans that could limit requests by allowing the cost of civil servants' time spent reading documents to count towards the £600 limit on the bill for responding to inquiries.
The move, which Lord Falconer denied is an attempt to limit access to information, has also been opposed by the Newspaper Society, which represents regional and local titles.
"It's not the case that journalists have been making frivolous requests," said spokeswoman Santha Rasaiah.
"If they had, the law already allows the public body to turn them down as vexatious or on grounds of cost.
"Regional and local papers up and down the country have used the act and got stories that are of great relevance to local people as a result of it."