Anti-monarchy demonstrations were held in over 50 cities across Spain Saturday in protest actions called by leftist groups. In Madrid over 15,000 people marched. Similar demonstrations were held in Barcelona, Valencia, Bilbao, Oviedo and many other Spanish cities.

Five days after Spanish King Juan Carlos announced his intention to abdicate the throne, the demonstrators demanded a referendum on whether Spain should continue as a monarchy or become a republic.

Monday, shortly after the abdication, a spontaneous outpouring of 20,000 people poured onto Madrid’s streets in a protest led by the 15-M anti-austerity movement. “Spain, tomorrow, will be Republican,” protesters chanted.

An El Pais poll, published Sunday, shows that nearly two thirds, about 62 percent, of Spaniards believe a referendum is necessary to decide whether Spain should continue to have a monarchy.

The United Left (IU), the third most powerful force in the Spanish Parliament, are considering a referendum that would call for state reform. IU leader Cayo Lara said a bill would be introduced in parliament seeking a referendum in the next three months.

King Juan Carlos, 76, made his surprise announcement on Monday, clearing the way for Crown Prince Felipe, 46, to become the country's next king.

Spain's legislature must pass special legislation to allow the announced abdication because the country's laws do not currently allow for abdication.

Spain's monarchy was installed by former dictator Francisco Franco. Juan Carlos has sat on the throne since 1975.