Mounting corruption allegations involving Prime Minister Pedro Sanchez’s family, allies, and party sparked the protest.
The protest was called by the Spanish Civil Society association, which said around 80,000 people attended, well above the government estimate of 40,000. Leaders from the opposition People's Party and the far-right Vox party also took part.
Police said three people were arrested. At least seven police officers were injured in clashes with protesters.
Graft allegations against Sanchez's inner circle A Spanish court announced on Tuesday that former Socialist prime minister Jose Luis Rodriguez Zapatero had been placed under criminal investigation over corruption allegations , a development that has again shaken the country.
Zapatero has been a major ally of Sanchez in recent years, and the court ruling has dealt a blow to Sanchez's Socialist party-led coalition. The news comes on the heels of graft cases involving Sanchez's family and members of his administration.
Sanchez, who took power in 2018 by ousting the scandal-hit conservative PP government in a no-confidence vote, has pledged to continue despite mounting graft allegations involving his circle.
Gomez has denied the charges, and Sanchez has dismissed the allegations as an attempt by the right wing to undermine his coalition.
Sanchez's younger brother, David Sanchez, is also due to stand trial this month over allegations of influence peddling. David Sanchez denies any wrongdoing.
Edited by: Louis Oelofse
