In a 10-minute televised address, Sánchez reflected on the wars in Ukraine and Gaza as well as the Iraq War more than 20 years ago and said the Spanish government’s position could be summed up as “no to war”.

Trump threatened to impose a full trade embargo on Spain in response to Madrid’s refusal to allow the US to use the jointly-run bases at Morón and Rotafor for strikes on Iran.

“Spain has been terrible,” Trump said during a meeting with German Chancellor Friedrich Merz on Tuesday.

“We’re going to cut off all trade with Spain. We don’t want anything to do with Spain,” he added.

Merz said later he had told Trump very clearly that he could not conclude a separate trade agreement with Germany or all of Europe but not with Spain.

In response to the US economic threat, the Élysée Palace said French President Emmanuel Macron had conveyed his “solidarity” with Spain, during a phone conversation with Sánchez on Wednesday. European Council President António Costa also said he had spoken to the Spanish leader “to express the EU’s full solidarity”.

Trump accused Spain on Tuesday of being a “terrible partner” in Nato for failing to increase its defence budget in line with a target of 5% of economic output (GDP).

Earlier this year Sánchez drew Trump’s anger by speaking out against the US military incursion into Venezuela.

In his televised address from the prime minister’s Madrid residence at La Moncloa on Wednesday, Sánchez said the government was studying economic measures to counter the impact of the conflict on Spaniards, although he avoided directly referring to Trump’s trade threat.

“The question is not if we are on the side of the ayatollahs – nobody is. The question is whether we are in favour of peace and international legality.”

“You cannot answer one illegality with another, because that is how the great catastrophes of humanity begin.”

Spain’s Socialist prime minister explained that the government’s position was comparable to its stance on Ukraine and Gaza. Sánchez has been a vociferous critic of Israel’s military response to the Hamas attacks in 2023.

Spain has been among Europe’s most outspoken governments on Gaza, describing Israel’s actions there as “genocide” and acknowledging a Palestinian state before many other EU members did.

That position was in step with his coalition partners to his left and, broadly speaking, with Spanish attitudes to the Middle East.

Looking back to the invasion of Iraq in 2003, which he said had failed to achieve its goals and had made life worse for ordinary people, he warned that the attacks on Iran could have a similar economic impact for millions.

His reference to the Iraq invasion will connect with many Spanish voters. Spain’s support at the time from the conservative People’s Party (PP) government was deeply unpopular, and triggered mass anti-war protests.

Many believe it also lay the groundwork for the Socialist Party’s surprise election victory in March 2004, days after Madrid was hit by deadly jihadist bombings.

Sánchez reminded Spaniards of the “Azores trio” of then-US President George W. Bush, the UK’s Tony Blair and Spanish conservative leader José María Aznar – who had met on a Spanish base in the region days before the Iraq invasion.

He said they had handed Europeans the “gift” of “a more insecure world and worse life”.

The Spanish leader’s stance contrasts strongly with that of Merz, who told German TV on Tuesday regime change in Iran would leave the world “a little better off”, although he also said this was “not without risk and we would also have to bear the consequences”.

Unlike Spain’s fellow Nato allies – the UK, France and Greece – it has not yet committed to any military involvement in response to the war.

The Spanish prime minister said he wanted to express the solidarity of the Spanish people with countries that had been “illegally attacked by the Iranian regime”.

Aside from the fierce criticism Sánchez is facing from the US, his coalition government has faced months of enormous political pressure, generating constant speculation that its collapse could be imminent.

It has been struggling to maintain its parliamentary majority, which includes an array of left-wing and regional nationalist parties.

Allegations of corruption against several of his allies and his inner circle have severely weakened his position.

In Spain’s deeply polarised politics, much of the support for Sánchez is driven as much by concerns about the country’s right and far right as it is by endorsement of his leadership and policies.

Standing up to the US president may have electoral benefits for the Socialist leader.

A recent poll by the CIS research institute found that 77% of Spaniards had a “bad” or “very bad” opinion of Trump, suggesting that even many right-wing voters might back Sánchez on this issue.

However, there is now uncertainty in Spain over whether Trump’s threats will translate into some form of economic reprisals, and many Spaniards will be watching this drama nervously.

Musk, who is set for a role as an adviser in United States President-elect Donald Trump’s administration, has provoked fury across Europe in recent weeks with a string of attacks on the continent’s leaders, including German Chancellor Olaf Scholz and United Kingdom Prime Minister Keir Starmer.

Musk also waded into Spanish affairs on Sunday by commenting on an article which stated that rape convictions in Spain’s Catalonia region were mainly carried out by foreigners.

Presiding over an event in Madrid to commemorate the 50th anniversary of the death of fascist dictator Francisco Franco on Wednesday, Sanchez accused Musk of heading an “international reactionary” movement that “openly attacks our institutions, stirs up hatred and openly calls for the support of the heirs of Nazism in Germany’s upcoming elections”.

“Autocratic regimes are advancing halfway around the world,” Sanchez said, warning that “the fascism we thought we had left behind is now the third political force in Europe” and adding that the far right is supported by “the richest man on the planet”, referring to Musk, whom he did not name.

The comments come after Musk offered strong support to the far-right Alternative for Germany (AfD) party ahead of snap elections in the country on February 23.

The billionaire has also called for Starmer to be removed and urged the release from jail of Tommy Robinson, a far-right UK activist who is serving an 18-month term for contempt of court.

The European Union is grappling with how to respond to Musk’s perceived interference. Some European governments are pressing the European Commission to use its legal arsenal.

“Either the European Commission applies with the greatest firmness the laws that exist to protect our unique space or it does not, and in that case, it should think about giving the capacity to do so back to EU member states,” French Foreign Minister Jean-Noel Barrot told France Inter radio earlier on Wednesday.

The issue is testing the EU’s willingness to confront Musk head-on and risk antagonising the incoming Trump administration, as well as the effectiveness of the bloc’s Digital Services Act (DSA), which regulates social media platforms’ operations in the EU.

A Commission spokesperson said this week that the DSA had previously proved to be an effective instrument to combat risks posed by the leading social media platforms and said a political choice had been made not to respond directly to Musk’s tweets and “fuel the debate”, the Reuters news agency reported.

Musk last month called German Chancellor Olaf Scholz an “incompetent fool” who should resign after a deadly car-ramming attack in Germany. On Thursday, Musk will use his platform to host a conversation with AfD head Alice Weidel.

Scholz has responded by calling for cool. “Don’t feed the troll,” he told German weekly Stern on January 4.

French President Emmanuel Macron took aim at Musk earlier this week.

“Ten years ago, who would have believed it if we had been told that the owner of one of the biggest social networks in the world … intervene directly in elections, including in Germany?” he said.

Musk has also been steadily critical of the UK’s Starmer and his government, most recently over a child sex abuse scandal more than a decade ago.

Starmer on Monday criticised “those that are spreading lies and misinformation as far and as wide as possible” without mentioning Musk by name.