The Protection of Information Bill poses a danger to our democracy, a member from the Umbilo Action group said during a march in Durban on Saturday.
"The bill poses a danger to our democracy. Our country is plagued with corruption and nepotism. If the bill is passed it will be difficult to demand accountability and transparacy," said Vanessa Burger.
Right to Know member Andrew Kerr said access to information was paramount in order to root out important.
"If the government tries to suppress information it will be a bad thing for everyone except the few people who benefit from corruption," he said.
Hundreds marched against the Protection of Information Bill in Durban and sang struggle songs.
They carried placards reading: "we have a right to know" and "keep the press free."
Marchers handed over a memorandum to a representative from the eThekwini municipality.
The document calls for a responsive and accountable democracy.
According to the memorandum, the bill threatens the constitution.
"It is one of a number of proposed measures which undermine the right of access to information and freedom of expression as well as compromising the protection of whistleblowers," the memorandum stated.