A member of the Russian feminist punk group Pussy Riot has launched a hunger strike to protest harsh conditions in a Mordovian penal colony where she is serving a two-year sentence for protesting Russian leader Vladimir Putin inside a Moscow cathedral.

In an open letter, Nadia Tolokonnikova describes “slavery-like conditions,” including beatings carried out with the approval of prison officials and sewing work shifts that last 17 hours. Tolokonnikova’s husband, Peter Verzilov, said she has also faced death threats.

Peter Verzilov: “Before this situation unfolded in the last several weeks, Nadia tried to change the situation internally, from inside the prison. But obviously she understood that this was impossible and at the end of her efforts, they just led to a murder threat from the prison administration.”

Tolokonnikova is one of two members of Pussy Riot now in penal colonies for the group’s “punk prayer” protest in 2011, when they danced and exhorted the Virgin Mary to get Putin out. The second member, Maria Alyokhina, staged an 11-day hunger strike earlier this year.