ANC negotiator Luwellyn Landers told the ad hoc committee of parliament processing the secrecy bill that the bill should be redrafted to ensure its constitutionality.
The concessions addressed at least three of the five fundamental concerns voiced by the SA National Editors Forum in a letter to all MPs this week.
Landers said the ANC would withdraw the clause setting mandatory prison sentences for all leaking of state secrets and drop any reference to minimum sentences.
This would leave it to the courts to decide how heavily leaking should be punished.
Landers said the clause giving the authority to classify to "all organs of state" would be redrafted, and state bodies other than those directly involved with security would have to apply for the right to classify and would not get it automatically.
He said also that the constitutionality of the bill should be tested beyond the assurance of the state law adviser, Enver Daniels, that it was compliant, but he did not say how that should be done.
Opposition MPs immediately congratulated the ANC and called the concessions "significant" but said there were remaining concerns that would have to be addressed.
Landers did not address the demand for a public interest clause that would allow whistle-blowers to offer a defence in court that the disclosure of a secret was in the public interest and should not be punished.
ACDP delegate Steve Swart asked the ANC to consider at least a limited public interest defence.
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