The Council of Europe has expressed serious concern at plans put forward by President Leonid Kuchma of Ukraine for a referendum on reform of the country's political bodies.

The president of the Council's parliamentary assembly, Lord Russell-Johnston, has said in a letter to Mr Kuchma that any reform should be carried under the existing constitutional arrangements, rather than by referendum.

Correspondents say that the proposed reforms would greatly enhance President Kuchma's powers at the expense of parliament.

The proposals have been one of the main factors contributing to deep divisions between the president's supporters in parliament and his opponents. In a BBC interview, Lord Russell-Johnston said that a Council of Europe delegation would visit Ukraine next week.

From the newsroom of the BBC World Service