The Government has been told that extra resources and staff will be required by the National Archives if State papers are to be released to the public after 20 years, in line with the current practice in the UK.

At present all Government departments are required to deposit their files with the National Archives when they are 30 years old. In Britain the so-called 30-year rule is being cut to 20 years on a phased basis.

Under a 2010 Act, UK files from 1983 were released in August 2013 rather than January 2014 as would previously have been the case.

Files from 1984 were released last month and there will continue to be two releases a year until 2022, when files from 2001 and 2002 will be released

There has been growing concern among Government officials and historians that unless Irish State papers are released earlier, the British view on key events in Anglo- Irish relations will be in the public domain long before the Irish files on the events are made public.

The National Archives Advisory Council, which advises the Minister for Arts, Heritage and the Gaeltacht, Jimmy Deenihan, has addressed the issue in its annual report for 2012.

Mr Deenihan presented the report to Cabinet yesterday. It says extra resources and staff will be needed to bring the release of State papers into line with the 20-year rule in the UK.

The National Archives is already overstretched, earlier annual reports state and this partly explains why so many departments have not been required to meet obligations to transfer files under the 30-year rule.

In practice many departments are out of date in transferring files to the National Archives. Only the departments of the Taoiseach and foreign affairs, and the office of the President and Attorney General appear to be in full compliance with their legal obligations.