Two members of the Russian punk group Pussy Riot who were jailed for singing an anti-government song in 2012 are headed to Sydney to headline the Festival of Dangerous Ideas.
Nadya Tolokonnikova and Masha Alekhina will discuss their views on President Vladamir Putin, the fight for their beliefs and what life was really like in the gulag at the event at the Opera House in August.
Wearing balaclavas over their heads, Pussy Riot used their music to draw attention to Putin's controversial third term in office. Their guerilla performances were supported by celebrities such as Sting, Madonna, The Red Hot Chilli Peppers and Paul McCartney.
Tolokonnikova and Alekhina were arrested for "hooliganism motivated by religious hatred" after they performed one of their songs in Moscow's Cathedral of Christ the Saviour church. They served two years in prison for the crime.
The festival's curator Ann Mossop says organisers had their eye on Pussy Riot for some time.
"They have a really interesting mixture of dangerous ideas and activism," Mossop said.
"It goes to a whole lot of really fundamental ideas about freedom of speech and the role of activism in combating what they perceive as political abuse of the Putin regime."
Pussy Riot will be joined by author Salmon Rushdie as the festival aims to focus on people who had paid a high price for their fearlessness in challenging existing status quos.
Rushdie's Booker winner novels Midnight's Children and The Satanic Verses were criticised by hardline Muslims.
In 1989 Iran's Ayatollah Khomeini issued a fatwa (death threat) against Rushdie which resulted in the author going into hiding for much of the 1990s.
Rushdie is also slated to appear at the Melbourne Writers Festival in August where he will deliver the keynote address on freedom of expression.
The Festival of Dangerous Ideas is on August 30 and 31 at the Sydney Opera House.
