"You won't find foreign spies openly marching in the streets of Cape Town, complaining that we are removing their easy access to our sensitive information, but they will fund their local proxies to defend their illegality," Cwele said during a heated debate of the Protection of State Information Bill in parliament yesterday.

But DA MP Dene Smuts told Cwele his comment "speaks of a paranoic approach. It is absurd".

She warned that corrupt intelligence services were more of a threat to the state than foreign spies.

IFP MP Mario Oriani-Ambrosini slammed the new law for insisting that anyone who comes across a classified document must return it to the authorities or face time in prison.

The law "imposes a string of obligations on members of the public to help the government keep the secrets for whatever reason it has failed to keep", he said.

Oriani-Ambrosini also argued it was unfair for MPs, journalists and members of the public to go to jail for speaking about a secret document leaked to them even if they had nothing to do with it being leaked.

A public-domain defence, which the ANC has refused to include, was common in the US, Canada and other countries, he said. This defence says that, once a secret has been leaked, it cannot be "unleaked" because it is already in the public domain.

But ANC MP Ben Fihla said a previous Constitutional Court judgment had found that classified documents that have been leaked into the public domain do not lose their classified status just because everybody knows about them.

Fihla admitted that the bill would affect media sources, who would be "out in the cold" once the bill was enacted.

African Christian Democratic Party MP Steve Swart said the bill must have a public-interest defence to protect members of the public who receive leaked documents and want to pass them on in order to expose corruption.

"No compelling argument was presented for not including a public-interest defence," he said.

DA MP David Maynier said "the question is not whether journalists will go to jail, but which journalist will go to jail first".

"The ANC wants to cover up unlawful acts, cover up inefficiency and cover up information that may cause embarrassment," he said.

MPs were to have voted on the bill in September but it was put on ice after it reportedly failed to get unanimous support from the ANC national executive committee.

ANC chief whip Mathole Motshekga promised then to hold public consultations, but it is unclear if these ever took place, because he never announced the details.

The IFP has since tabled 123 amendments to the bill, which must now be discussed by a parliamentary committee before a vote can take place.

Cosatu spokesman Patrick Craven said if the bill was passed in its current form, the union federation would challenge it in the Constitutional Court.

Craven called for the bill to be sent back to the South African Law Reform Commission to be rewritten.

Cosatu was concerned that the bill had been brought back to parliament without a single public meeting in the provinces as promised by the ANC, Craven said.

It was dangerous that Cwele could give "just about any organ of state or national keypoint (including private institutions)" the right to classify information.

The bill could also undermine the right to access information available through the Labour Relations Act, Craven said.