Representatives of the 39 member-nations, meeting in Strasbourg, said they will draw up a list of conditions for Croatia to meet before they approve its membership.
Their decision marks the first time in the 47-year history of the Council that the member-nations have gone against a vote by the organisation's parliamentary assembly. It reflects growing European concern about the authoritarian ways of Croatia's President, Franjo Tudjman.
The council is best known for its 1950 European Human Rights Convention, which enables citizens of member-nations to challenge their governments for suspected civil- rights abuses in a special court.
Its parliamentary assembly voted on 24 April to admit Croatia, despite misgivings about Mr Tudjman's government. Normally Croatia's entry would be rubber-stamped by the organisation's foreign ministers.
But the European nations felt obliged to take the unprecedented action of delaying membership after Mr Tudjman vetoed the election of an opposition mayor of Zagreb and cracked down on the independent media. "Consensus on the eventual accession of this country is still a long way off," the Council said in a statement.
On Monday foreign ministers from the 15-nation European Union said Croatia's membership of the Council should be allowed only if it meets certain conditions. A detailed list of conditions is expected to be drawn up by the members' ambassadors on 30 May. It is likely to include guarantees of press freedom, protection of minorities, compliance with the Balkan peace agreement and co-operation with the international war-crimes tribunal for former Yugoslavia.
Letters, page 14