LISBON, Portugal — Spain's Supreme Court on Thursday turned down a second request by a jailed leader of Catalonia's independence movement to be released so regional lawmakers can vote on making him their leader.

Judge Pablo Llarena said in a ruling that there remained a risk that Jordi Sanchez, a prominent Catalan secessionist, would repeat the offenses that landed him in a Madrid jail.

He is being detained while the Supreme Court investigates whether he orchestrated protests that hindered officials who were trying to stop a court-banned Catalan independence referendum last October. The ballot triggered Spain's worst political crisis in decades.

Pro-independence political parties in Catalonia have defied the Spanish government for the past six months with efforts to secede from Spain and create a new country. Court rulings have repeatedly thwarted their ambitions, however, because the Constitution says Spain is "indivisible."

Llarena said the only new argument in Sanchez's latest request was a reference to the U.N.'s Human Rights Committee calling for Spain to respect the rights of arrested Catalan separatists. The judge said the U.N. body had made no specific demands.

Llarena also denied Sanchez's request to appear in the Catalan parliament via a video link.

Sanchez, who was elected to the Catalan parliament in December, hoped to attend a parliamentary session Friday where the slender majority of pro-independence lawmakers were to debate making him Catalan president.

Following the Supreme Court ruling, Catalan parliament Speaker Roger Torrent announced the postponement of Friday's investiture session.

The northeastern region of Catalonia, Spain's wealthiest, has been without its own government since an election in December that was called by Spain's national government in Madrid in an attempt to end a standoff with secessionists.

Spanish authorities are showing no sign of letting up on pursuing legal charges against those behind the independence movement.

Llarena last month charged 13 leading Catalan separatist politicians with rebellion for their attempts to make the region independent and ordered that international arrest warrants be issued for six who fled the country.

Former regional President Carles Puigdemont was arrested in Germany. They are all fighting extradition.

The lawyer for one fugitive, former Catalan government minister Clara Ponsati, said in a Scottish court Thursday that the Spanish arrest warrant should be considered invalid because the politician has committed no crime under Scottish law.

Ponsati, a professor at St. Andrews University in Scotland, was arrested last month at Spain's request.

Her lawyers said during a Thursday hearing at Edinburgh Sheriff Court that they would fight extradition on the validity of the warrant and Ponsati's human rights. The case will be heard in July.

Outside court, attorney Aamer Anwar accused Spanish authorities of "prosecuting Clara for her political opinions."

Also Thursday, Spanish prosecutors requested pre-trial detention for a woman believed to be a leader of Catalonia's Committees for the Defense of the Republic, a grassroots group that organizes protests. The court did not name her.

The public prosecutor argued that her actions had led to violence in the streets and asked the National Court to charge her with rebellion, but a judge recorded a lesser charge of public disorder and ordered her released.


Jill Lawless in London contributed to this report.