JOHANNESBURG (AP) — South Africa’s parliament prepared Monday for a vote the following day on a state secrets bill that critics within and outside the governing party said would smother freedom of expression and make it harder to fight corruption.

The African National Congress, which holds a majority of parliament’s seats, sponsored the bill, making it likely it would become law.

The ANC said South Africa needs to update apartheid-era legislation defining state secrets and imposing penalties for their disclosure. The party bristles at suggestions from critics that its proposal would take the country back to the days of white rule, when the government banned newspapers and punished whistle blowers to stifle criticism of its policies.

An umbrella organization of rights and development activists, historians and legal experts said in a statement last week that the bill could erode "the right to information in South Africa without justification."

In June, the ANC backed down on some of its original proposals, responding to months of criticism from newspaper editors, prominent writers led by Nobel laureate Nadime Gordimer, church groups, freedom of expression lobbyists, business leaders and others. Prominent ANC members also have opposed the bill, among them a former state security minister.

The changes included removing mandatory prison sentences for possessing and publishing secrets — though reporters and others could still be jailed for publishing information that officials want kept secret. The ANC also agreed to limit the power to classify secrets to state security agencies, and proposed that an independent official — a retired judge — review appeals of state security rulings on classified information.

While those amendments were welcomed, the National Press Club was among those calling for more concessions, including a provision allowing those who break the law to avoid going to jail if they could argue they acted in the public interest.

In a speech to parliament last week, State Security Minister Siyabonga Cwele said the public interest defense could not be accomodated. Cwele, whose ministry is sponsoring the bill, said that once secrets were out, the harm was done, even if a judge later ruled the public had no interest in their disclosure and the leaker was punished.

Cwele took a hard line, saying foreign spies were stealing information "at the expense of advancement of South Africa and her people," and even raising the possibility that demonstrators who have held peaceful marches to rally opposition to the bill were somehow being used by South Africa’s enemies.

Critics like the Congress of South African Trade Unions, an influential labor group that traditionally supports the ANC, say even the amended bill puts too much power in the hands of government.

In a recent statement, the labor group said it was concerned the bill could make criminals of "individuals who disclose information in the public interest."

The secrets bill is separate from another ANC proposal that has raised concerns — the possible creation of a tribunal that could discipline journalists, with powers to punish that have not yet been spelled out.

Activists fear the recent moves in South Africa — known for one of the continent’s freest and most open constitutions — could influence other countries in the region.

Relations between the ANC and the media long have been tense. Last week, one of the country’s most prominent newspapers, the Mail & Guardian, said it had been unable to publish details about corruption allegations against Mac Maharaj, a longtime ANC leader who recently took on the job of presidential spokesman, because of threats of criminal prosecution. Maharaj later announced he was asking police to investigate whether the paper and its journalists had broken the law in their reporting.