Mohamed Nasheed, who was the Indian Ocean archipelago's first democratically elected leader, was sentenced to 13 years in prison last year for ordering the arrest of a senior judge while in office.
In January, he was granted a medical leave to travel to Britain, apparently to undergo back surgery.
Nasheed's office quotes him as saying today that he and other opposition politicians feel that they "have no choice but to work in exile for now," claiming that the Maldives is sliding toward authoritarianism.