The government is planning to introduce important new restrictions on access to cabinet and royal papers under freedom of information.

Under the new plans, cabinet papers would be absolutely exempt from FOI for a period of 20 years. This would include records relating to cabinet sub-committees.

This would be significantly tighter than the current position, where for most cabinet documents the decision on whether to release them depends on the "public interest test" - whether it is more in the public interest to disclose them in response to an FOI request or to keep them secret.

Royal papers will also be subject to an absolute exemption for 20 years, which in the case of the sovereign and the heir to the throne would be extended to five years after their death if that was later.

The Ministry of Justice has confirmed that this is what Gordon Brown meant when in his Commons statement today he referred to "the need to strengthen protection for particularly sensitive material".

This will be accompanied by greater openness for government papers apart from cabinet and royal documents, reducing the "30 year rule" which governs when most of them will be open to the public to 20 years. This is the government's response to the recent Dacre review of the rule.

Mr Brown also confirmed that FOI will be extended to cover a wider range of organisations. The justice minister Michael Wills had already indicated this last month.

The next step on this would involve consultation with those bodies that the government wants to bring within the scope of FOI, so it will be some time before any extension actually takes effect.

Mr Brown told MPs:

"Given the vital role transparency has played in sweeping aside the discredited system of allowances, and holding power to account, I believe we should do more to spread the culture and practice of freedom of information."

UPDATE 17.50: The Ministry of Justice has now given me this statement:

"The Dacre Review's recommendation that we consider - in parallel to adopting a new rule - whether certain categories of information deserve enhanced protection has prompted us to look at important safeguards in the current FOI Act. In relation to Cabinet information, and information relating to the Royal Household, it has become clear that those safeguards are insufficiently robust to protect our current constitutional arrangements, and need changing. We will be announcing the detail of these changes in our full response, to be published shortly. We will be making two amendments to the exemptions in the Freedom of Information Act to ensure that our information access arrangements allow essential constitutional relationships and conventions to be preserved. "Cabinet papers will be released much earlier than under the current rule, but will be subject to an absolute exemption under the Act until they are 20 years old. "To ensure the constitutional position and political impartiality of the Monarchy is not undermined, the relevant exemption in the Freedom of Information Act will be made absolute for information relating to communications with the Royal Household that is less than 20 years' old. After that point - if the relevant Member of the Royal Family is still alive - then the exemption will continue to apply until five years after their death - on an absolute basis for the Sovereign and the Heir to the Throne, and on a qualified basis for other members of the Royal Family."

The Campaign for Freedom of Information is not happy.

