An attorney says the Maldives government has reneged on its promise to allow the country's imprisoned ex-president to have surgery abroad without conditions and is now demanding that a family member guarantee his return or face prosecution.

Former President Mohamed Nasheed was to have left Sunday for Britain to have spinal surgery after the government announced he could seek treatment abroad.

But Nasheed's attorney, Hassan Latheef, says the government has now set a 30-day limit for Nasheed 's stay abroad and also is demanding that a family member remain in the capital as surety and face prosecution if Nasheed fails to return.

Elected the country's first democratically elected president in 2008, Nasheed now is serving a 13-year prison sentence for ordering the arrest of a senior judge when he was president in 2012.