Mikheil Saakashvili is in “critical condition” and his medical needs are not being met, a group of doctors sent by Georgia’s public defender said in a statement.
The doctors requested his transfer to an intensive care unit in a civilian hospital, something the government has refused.
Saakashvili returned to Georgia ahead of local elections to boost support for the opposition after spending years in exile in Ukraine.
He had been convicted in absentia of abuse of power during his 2004-2013 presidency and was arrested upon his arrival in the country.
He has been on a hunger strike for 48 days in protest of his incarceration.
Saakashvili was transferred to a prison hospital last week due to his deteriorating condition.
The 53-year-old former leader said he was mistreated by his guards in prison and said he feared for his life.
The European Court of Human Rights said on November 10 that the Georgian government should “ensure (Saakashvili’s) safety in prison and provide him with appropriate medical care.”
Several thousand people have rallied in support of the former president, and several opposition politicians have also gone on hunger strike. They demand that he be transferred to a civilian hospital.