LONDON: The government of Mauritius has threatened to leave the Commonwealth so that it can take Britain to the international court of justice for the return of the Chagos islands in the Indian Ocean.

The archipelago includes Diego Garcia, where the US has strategic air and naval bases. The Mauritian Prime Minister, Paul Berenger, will fly to London on Friday to discuss withdrawal with the Commonwealth secretary general, Don McKinnon.

Mauritius is barred from going to the court by a colonial-era rule which prevents Commonwealth members taking legal action against Britain. Joel Kibazo, a Commonwealth spokesman, said: "We hope this issue can be resolved because Mauritius is an important member of the Commonwealth and no member wants (it) to leave."

It is unusual to leave the Commonwealth voluntarily: Pakistan, Fiji and South Africa all left but were later re-admitted. Zimbabwe left in December after a row about human rights abuses and other democratic rights.

The Chagos islands lie about 600 miles north of Mauritius, which has been campaigning for more than 30 years for their return. Britain hived them off in 1965, three years before granting independence to Mauritius, and declared them a British territory to make way for the US base.

It evacuated the resident population of about 1,500 to Mauritius. The US opposes the islanders' return on security grounds. Mr Berenger is acting in response to an order by the Foreign Office minister Bill Rammell on June 10 barring their return.

The British Foreign Office said on Tuesday it had been told of the threatened withdrawal on Monday. "We would be disappointed and we do not want them to leave the Commonwealth," its spokesman said. "It is up to them."

The Mauritian deputy high commissioner, Haymandoyal Dilium, said there were a number of options under consideration, but leaving the Commonwealth was the only way Mauritius could take Britain to court.

He wrote to Tony Blair about the issue several months ago and is angry that he has not yet received a reply. One of those involved in the diplomatic row said a significant compromise by the British government would be needed in the next few weeks to head off the threat. -Dawn/The Guardian News Service.