The US administration’s National Security Agency (NSA) not only combed the telephone conversations, text messages and emails of millions of Spaniards, but it also spied on members of the Spanish government and politicians, according to sources who have knowledge of the secret documents in the possession of whistleblower and former NSA analyst Edward Snowden.

Even as other European leaders, led by Germany and France, discussed a response to the revelations that the NSA had spied on top officials in allied nations around the world, the Spanish government maintained official silence to avoid damaging relations with Washington. Amidst widespread indignation at the Brussels summit of European Union leaders, Prime Minister Mariano Rajoy made no comment, and his conservative administration has tried until the last moment to play down the possibilities of NSA spying having targeted Spain.

On Thursday morning a high-ranking official insisted that the Rajoy government was “unaware” that the NSA had operated a large-scale espionage operation in Spain. However, the administration member added: “If this were the cease, it would have taken place in the [Prime Minister José Luis Rodríguez] Zapatero era.” The phrase made clear that the Spanish administration already knew more than it was letting on in public; or that it was keen to distance itself from the issue by describing such abuses as something which affected the previous government, and therefore, was not something it could have avoided.

Spain’s CNI intelligence service has assumed that Spain was among the long list of countries affected by Washington´s espionage operations, but did not consider it likely that individual politicians had been targeted. In July Defense Minister Pedro Morenés declared: “I have not been spied on, and in general I don’t think it has been generalized thing.”

After Wednesday’s revelation that German Chancellor Angela Merkel’s cellphone communications had been intercepted, such confidence began to melt away. “What I care about now is Rajoy’s cellphone,” said a prime-ministerial aide on Thursday.

At a media conference in Brussels on Friday afternoon, Rajoy said that the only decision he had taken so far on the NSA spying issue was to ask the US ambassador in Spain to provide explanations. Asked whether he would join the Franco-German initiative to demand answers from US President Barack Obama, Rajoy said that he would take such that decision "in due course," adding that he did not have the awareness that those two fellow European government did of having been a victim of NSA espionage.

A statement agreed by the 28 EU leaders gathered in Brussels says that "a lack of trust could prejudice" intelligence-gathering co-operation.