Spain’s Constitutional Court is “blocking” Catalan separatists’ attempts to seek justice in Europe. This is according to a letter signed by four Catalan independence leaders who are on a hunger strike in prison.

The four separatists are awaiting trial for rebellion over their role in last year’s unauthorised referendum and subsequent unilateral declaration of independence.

In their message to the heads of European nations and EU officials, the four men detail how Spain’s Constitutional Court is, in their view, “blocking” all their appeals, in order to prevent them from getting their cases to the European justice system.

As reported by the Spanish newspaper El País, their spokeswoman, Pilar Calvo said that ex-Catalan government members Jordi Turull, Josep Rull and Joaquim Forn, as well as Jordi Sànchez, former head of the pro-independence civic organization ANC and currently a regional deputy, want to draw attention to their situation.

“There are nine of us and we have been in prison without trial for over a year, accused of rebellion for calling a peaceful referendum. Our rights to the presumption of innocence and to a fair trial are being violated,” says the letter, a copy of which has also been mailed to Spanish Prime Minister Pedro Sánchez.

On December 21, Sánchez will hold a Spanish Cabinet meeting in Barcelona. But pro-independence groups have announced they will boycott with extensive street protests.