Spain’s Prime Minister Mariano Rajoy faces the country's toughest constitutional crisis in decades after Sunday's violent independence referendum in Catalonia opened the door for its wealthiest region to go for secession as early as this week.

The streets of Catalan capital, Barcelona, were silent on Monday, but newspaper editorials stated that the banned referendum, in which Catalan officials said 90% of voters had chosen to leave Spain, had set the stage for a key clash between Madrid & the region.

Catalonia's regional leader confirmed late on Sunday that voters had earned the right to independence & said he’d present the results to the region's parliament, which then had the power to move a motion of independence.

The euro lost a third of a United States cent after the vote, though it later recovered ground.

Catalan trade unions have called a general strike for Tuesday.

At home, the crisis doesn’t seem to have endangered support for Rajoy's minority national government, with mainstream parties mostly backing his opposition to Catalan independence.

The Catalan government said 2.26 million people had cast ballots on Sunday, a turnout of about 42%, even with the crackdown.