The European Union has demanded that Venezuela end its oppression of opposition leaders and free all political prisoners, the bloc's top diplomat Josep Borrell said on Sunday.

The EU's call came after Spain on Sunday said it will grant political asylum to Venezuelan opposition leader Edmundo Gonzalez Urrutia, who has quit Caracas after a month in hiding in the crisis-hit South American country.

"The EU insists that the Venezuelan authorities end repression, arbitrary arrests and harassment against members of the opposition and civil society, as well as release all political prisoners," Borrell said in a statement.

Borrell said Gonzalez Urrutia "faced repression, political persecution, and direct threats to his safety and freedom" before seeking to go into exile in Spain.

"Today is a sad day for democracy in Venezuela," said Borrell, adding "in a democracy, no political leader should be forced to seek asylum in another country".

Gonzalez Urrutia -- who disputed President Nicolas Maduro's July 28 re-election -- left Venezuela after ignoring three successive summons to appear before prosecutors, arguing that attending the hearing could have cost him his freedom.

Madrid's Foreign Minister Jose Manuel Albares said that Gonzalez Urrutia had requested political asylum in the European country, and that Spain would "obviously" grant it to him.

He earlier confirmed on X that the opposition leader had departed on a Spanish military aeroplane, adding that Spain was "committed to the political rights" of all Venezuelans.

Caracas said it had agreed to his safe passage.