File picture - A demonstrator protests against the passing of the Protection of State Information Bill outside Parliament in Cape Town.

The National Council of Provinces extended the reporting deadline of its ad hoc committee processing the Protection of State Information Bill by six weeks to June 30 on Wednesday.

Last week, the ANC proposed several amendments to the bill in response to sustained criticism over the past years.

It notably suggested writing a cause into the draft act to protect those who expose classified information to expose corruption.

Critics have cautiously welcomed the concessions, but said more were needed to make the legislation constitutional.

It has been criticised as an onslaught on freedom of expression.

The department of state security is expected to present its views on the proposals to the ad hoc committee in coming weeks. - Sapa