South African journalists have launched a campaign against proposed legislation which they say would curtail press freedom and threaten democracy.
In a declaration published in papers on Sunday and Monday, more than 30 prominent editors called on the government to abandon the planned laws.
The proposals would allow the government to classify material that is currently not secret.
And a special tribunal could fine or jail journalists for inaccuracies.
The ruling African National Congress (ANC) says new legislation is needed to make journalists legally accountable for inaccurate reporting.
"Free speech and access to information are the lifeblood of our democracy and we are at the very heart of the struggle for freedom," the editors' statement, known as the Auckland Park Declaration, said.
"We appeal to the South African government and the ruling ANC to abide by the founding principles of our democracy, and to abandon these proposed measures."
BBC Africa analyst Martin Plaut says the new laws would leave journalists facing jail terms of between five and 25 years, if they disclose information prejudicial to the country.
Even possession of classified documents would be an offence, he says.
Some journalists have said the planned tribunal reminds them of methods used to control journalists during the time of apartheid.
Last week, the Law Society of South Africa (LSSA), which represents the country's 20,000 lawyers, said the proposed legislation contains a definition of "national interest", which was "so broad that it could potentially cover every aspect of a citizen's life".
The co-chairperson of the LSSA, Max Boqwana, said the legal plans would tarnish South Africa's reputation as a free country.
"Quite honestly it will be a sad day, not only for the media but for democracy," he told the BBC.
"We continue to pride this nation as the country that has got one of the best entrenchment of freedoms throughout the civilised world.
"And, this will not have, only a negative impact on the media, but it will have a negative impact on our country in general."