HUMAN right judges have condemned Spain for convicting two Catalan men who set fire to a picture of King Juan Carlos I and Queen Sofia during a protest more than a decade ago.

Seven judges at the European Court of Human Rights in Strasbourg unanimously ruled that Spain had violated Article 10 (freedom of expression) of the European Convention on Human Rights in the case against Stern Taulats and Roura Capellera.

The pair set fire to pictures of the royal couple in Girona in December 2007, during a protest outside the town hall during visit to the city by the royal couple.

Judges found the act “had been part of a political, rather than personal, critique of the institution of monarchy in general and in particular of the Kingdom of Spain as a nation”.

They ruled it had not constituted incitement to hatred or violence, and that the 15-month prison sentence – later replaced with fines of €2700 (£2396) each – was an interference with their right to freedom of expression It was not a personal attack on the king, but part of a debate on Catalan independence, an issue of general interest, the monarchic structure of the state and a critique of the king as a symbol of the Spanish nation.

The court ordered Spain to pay Taulats and Capellera €2700 each in pecuniary damages and €9,000 (£7988) each for costs and expenses.

Their lawyer, Benet Salellas, said in a statement: “The ruling makes it very clear that political criticism against the institutions of the state will never be a discourse of hatred. It is an amendment to the whole of the Spanish justice system.”

Spain’s use of anti-terrorism legislation has come under fire from human rights group Amnesty International, which described it as “a sustained attack on freedom of expression”.

Amnesty said in a report that scores of ordinary social media users, musicians, journalists and even puppeteers had been prosecuted on the grounds of national security, which had had a “profoundly chilling effect”.

This had created an environment where people were increasingly afraid to express alternative views or make controversial jokes.

“Sending rappers to jail for song lyrics and outlawing political satire demonstrates how narrow the boundaries of acceptable online speech have become in Spain,” said Esteban Beltrán, director of Amnesty International Spain.

“People should not face criminal prosecution simply for saying, tweeting or singing something that might be distasteful or shocking.

“Spain’s broad and vaguely-worded law is resulting in the silencing of free speech and the crushing of artistic expression.”