The African National Congress (ANC) agreed on Tuesday to some of State Security Minister Siyabonga Cwele's hawkish proposals on the Protection of State Information Bill.

Cwele notably appeared to have persuaded the ruling party to re-introduce a maximum five-year prison sentence for the disclosure of classified information, and to re-introduce a clause that would have the new law trump any other legislation dealing with such information.

Without explicitly naming the Promotion of Access to Information Act, the new official secrets act would therefore trump it – as Cwele has asked for, and commentators have cautioned could render the bill unconstitutional.

ANC MP Sam Mozisiwe also indicated that the party would water down the protection afforded to whistleblowers and the media in section 43, more or less along the lines proposed by the minister a fortnight ago.

But the party would not bow to Cwele's argument that the threshold for liability be lowered by re-inserting the term "ought reasonably to have known" in the offences clauses in the contentious law.

"We have looked into that and unfortunately for now we are unable to agree with the department on that," Mozisiwe said.

The Democratic Alliance and the Congress of the People said they were disappointed with the ANC's decisions, especially to limit the protection given to whistleblowers under clause 43.

"We need to add to make this a substantial exemption clause in place of a public interest clause," said DA MP Alf Lees.

The opposition, rights groups and the ANC's alliance partner, the Congress of South African Trade Unions, have all argued in vain for a public interest principle to be written into the bill as a legal defence for those charged with revealing state secrets.

But the ANC has always ruled it out, with Cwele saying it would amount to tearing up the bill before it became law.

The minister has been widely criticised for putting his views to the department last month, with opposition parties saying he was flouting the separation of powers.

The minister and the party have defended it as a salutatory exchange of views.

"We have agreed to some of their proposals, which is quite a number of them, and we have also disagreed with some of their proposals," said the ANC's Teboho Chaane, the acting chairperson of the ad hoc committee finalising the bill in the National Council of Provinces (NCOP).

Chaane scheduled another meeting for Wednesday to finalise deliberations on the bill, before political parties will vote on it in committee.

After two-and-a-half years of controversy, it is due to be debated in the NCOP by month's end.

It then has to be sent back to the National Assembly, which will be able to deal with it only in the new year.