Spain's top court has upheld a decision to ban Catalonia's separatist leader Quim Torra from holding public office.
The case stems from Mr Torra's refusal to take down a pro-independence symbol from a government building ahead of last year's general election.
He was found guilty of disobeying a court order to remove the banner, and will now be forced to stand down.
The Supreme Court's decision to uphold Mr Torra's 18-month ban triggered immediate calls for protests.
It is not yet clear when the ban will take effect, but Catalonia's high court is expected to rule on this imminently.
Catalonia, home to Barcelona, is a semi-autonomous region in north-eastern Spain with about 7.5 million people.
Its drive for independence plunged Spain into its biggest political crisis in 40 years in 2017. The region had its autonomy suspended for almost seven months by Madrid after a failed bid to break away.
"[Mr Torra] repeatedly and stubbornly disobeyed the orders of the Central Electoral Board to remove certain symbols from public buildings belonging to the [regional government] during the electoral process," the Supreme Court judges said in their ruling on Monday.
The 57-year-old defended himself on the grounds of freedom of expression and had been appealing against an earlier verdict in a lower court.
But the judges said he had defied a constitutional body and rejected his appeal.
It is believed deputy Catalan leader Pere Aragones will become the region's acting head.
Mr Torra, a staunch separatist, was elected in May 2018 as a relative newcomer to politics. He pledged that his new government would "build an independent state in the form of a republic"
In October last year, the Supreme Court sentenced nine Catalan politicians and activists to jail terms of between nine and 13 years over the 2017 independence bid.
"Supreme shame," Jordi Turull, one of the jailed leaders, wrote on Twitter after Monday's ruling.
"Once more, the Spanish state interferes in our democratic institutions," Mr Torra's predecessor, Carles Puigdemont, wrote.