Official Government documents previously made public only after a lapse of 30 years are to be accessible in future after a five-year period.
The dramatic change in the time limit for access to sensitive Cabinet papers comes under a provision of the Freedom Of Information (FOI) Act.
Under Section 19 of the Act, from April 21st next details of decisions taken by the Government five years before can be requested and released, the Ombudsman and Information Commissioner, Mr Kevin Murphy, has revealed.
Up to now, secret Government documents have only been released after 30 years under existing provisions.
"This position will change from April next year when the Act will have been in operation for five years. In other words, from then on, on a rolling basis, papers relating to government meetings will be open to an FOI request on the fifth anniversary of the meetings concerned," said Mr Murphy.
The new disclosure regime means decisions involving the Taoiseach, Tánaiste, and most of the current Cabinet who were in power in April 1998 can be revealed.
Among the big political events after April 1998 were the resignation of Mr Ray Burke as Minister for Foreign Affairs, the passing of emergency anti-terrorism legislation following the Omagh bombing, and the deregulation of the telecom sector. The first Government study into the so called "Bertie Bowl" was also commissioned that year.
The media, historians and members of the Oireachtas will use the Act to access papers and to get an insight into how key government decisions were made.
The FOI Act provides for consultation with leaders of political parties involved in government at the time a decision was taken before material can be released. However, party leaders do not have the power to veto the release of sensitive papers.
A FOI lawyer said last night ministerial briefing papers, advisory papers, memoranda for government, aides' memoirs and drafts of Cabinet records will all be accessible under the Freedom of Information Act. Discussions at Cabinet will not be accessible.
Government papers pre-April 1998 will still be subject to the 30-year-rule. However, legal experts said it is hard to see the Government justifying maintaining the rule now that documents from 1998 can be accessed.
When Section 19 of the FOI Act kicks into place, the level of access to confidential government material will be unprecedented among Western democracies. In most other countries the material is regarded as secret for periods of between 10 and 30 years.
Mr Murphy made the revelation in a wide-ranging interview with a new bi-monthly public affairs magazine, Public Affairs Ireland, which is published today.
In a hard-hitting interview, he accused the Government of having no "clear philosophy" towards the role of Ombudsman. He called for all bodies covered by the FOI Act to also be covered by Ombudsman legislation.
Mr Murphy criticised the "continued defensiveness" of some public servants to complaints from the public, and called for public servants to take administrative accountability as seriously as financial accountability. "Unless the general public feel that public services are administered properly, fairly and impartially there will be growing cynicism and alienation between government in its widest sense and citizens."
He repeated recent public criticism of the Revenue Commissioners. He said they regarded it as a "test of their virility" when the Ombudsman decided to investigate cases which may result in money payments by them.
He said other public servants, such as county managers, are sometimes sensitive about their very wide-ranging discretionary powers being subject to external scrutiny.
Mr Murphy singled out the health and insurance sectors where, he said, complainants were often dealt with in a very adversarial manner.