The first democratically elected president of the Maldives says from exile in Britain that he has an agreement with the country's former strongman to counter the sitting president, who is increasing his stranglehold on power.

Speaking to reporters via Skype on Tuesday night Mohamed Nasheed said he and his predecessor Maumoon Abdul Gayoom have an agreement to fight his half-brother President Yameen Abdul Gayoom. He declined to give details.

Maumoon ruled Maldives for 30 years with tight controls and repeatedly jailed Nasheed, who was then a pro-democracy activist. In his last years as president Maumoon allowed for multiparty democracy and oversaw the enactment of a democratic constitution that paved the way for Nasheed's election in 2008.