Ska Keller, the co-chair of the Greens/European Free Alliance group in the European Parliament, has called on Spain’s public prosecutor to drop charges of rebellion against Catalan leaders to be tried for organizing a referendum and declaring independence a year ago. “There is no real case for it. We’ve already seen courts in Belgium and in Germany saying that there is no cause to assume that there was rebellion or sedition,” she said on Monday.

Keller visited politicians held in pre-trial jail in Lledoners, in central Catalonia, including former vice president Oriol Junqueras, as well as Jordi Sànchez, one of the most prominent pro-independence activists at the grassroots level last October.

In total, nine people are preemptively imprisoned for their role in the independence bid, some of whom have been in jail for almost a year. All their petitions for freedom while awaiting trial have been rejected. “It’s not understandable why they have to sit in prison while the trial starts,” said Keller. “There will be a trial, they will defend themselves, but why spend so much time in prison before there’s even a trial?”

A member of the (EP) since 2009 for Germany’s Green party, Keller became the party’s frontrunner in the 2014 European election.

Keller was accompanied by two of her colleagues in the Greens/EFA group, Ernest Urtasun and Jordi Solé.