Unrest swept across the nation in June (13) when police tried to forcibly move peaceful demonstrators who were camped in Istanbul's Taksim Square in a bid to halt a planned redevelopment of the area.
Violent clashes followed as political activists took to the streets to show their dissatisfaction with Prime Minister Tayyip Erdogan's government and the introduction of strict conservative policies.
As protests in the country continue, a number of luminaries from the worlds of film, history and law have come together to write an open letter accusing Erdogan of using "heavy-handed" tactics which have allegedly led to the death of five demonstrators.
The missive, taken out as an advertisement in Britain's The Times newspaper, reads, "We, the undersigned, write this letter to most vigorously condemn the heavy-handed clamp down of your police forces on the peaceful protesters."
The letter goes on to accuse Erdogan's government of "relying on untold brutal force" and having "told disregard" for the five protesters who died during clashes.
As well as Sarandon, Penn and Kingsley, the letter is also signed by director David Lynch, actor James Fox, Oscar-winning screenwriter Sir Tom Stoppard and Downton Abbey creator Julian Fellowes.