As a leading Catalan politician renewed calls for an investigation, Spain’s Socialist-led coalition government has emphatically denied any involvement in the use of spyware to target senior members of the Catalan independence movement, saying: “This government doesn’t spy on anyone.”

A joint investigation by the Guardian and El País has determined that the mobile phones of at least five members of the regional independence movement – including the speaker of the Catalan parliament – were targeted using powerful software its makers claim is sold only to governments.

The reports have prompted calls for a parliamentary investigation and two of the alleged victims have already said they will take legal action against Félix Sanz Roldán, who was the head of Spain’s National Intelligence Centre (CNI) at the time of the targeting in April and May last year.

Roldán told the Guardian this week the CNI “always acts with the most scrupulous regard for the law”, and said he had nothing more to add.

Spain’s interior ministry, meanwhile, has said the actions of state security forces are always conducted “with the utmost respect for the law”.

In an interview with the online newspaper elDiario.es on Sunday, Carmen Calvo, Spain’s senior deputy prime minister, was blunt when asked if the government had engaged in spying.

“Absolutely not,” said Calvo, adding that neither the current coalition nor the Socialist minority administration that preceded it “have anything to do with situation like this one … This government doesn’t spy on anyone”.

She said the legal action against Roldán announced by the speaker of the Catalan parliament, Roger Torrent, and the former regional foreign minister, Ernest Maragall, was proof of the legal recourse available to those in public service under the rule of law.

“But I repeat, this government doesn’t spy on its political opponents,” said Calvo. Rather than spying on them, she added: “We recognise that our political opponents are there and we talk to them and sit down with them.”

Her comments came as the Catalan vice-president, Pere Aragonès, said “espionage is also a form of repression”, adding that he could not understand why public prosecutors were not already investigating the matter.

“There’s proof that a hack was conducted against the phones of Roger Torrent, the speaker of the Catalan parliament, and the former minister Ernest Maragall,” Aragonès told El País on Sunday.

Aragonès – who, like Torrent and Maragall is a member of the pro-independence Catalan Republican Left party (ERC) – also pointed to media reports that allege Spanish intelligence services possess the spyware in question.

“What I ask myself is how it is it possible that public prosecutors haven’t opened a legal investigation,” said Aragonès. “It this was the other way round, I’m sure they would have.”

The regional vice-president also said he had not received any calls from the central government to explain what it knew – or did not know – about the alleged targeting.

Asked if he had called them, he said: “They’re the ones who need to be providing explanations.”

The allegations came ahead of possible Catalan elections in the autumn and as the government prepares to bring its 2021 budget before parliament. In the past, iministers have had to rely on the support or cooperation of the ERC to get key measures through congress.

The tensions will also complicate negotiations aimed at finding a political solution to the so-called Catalan question.

The NSO Group, which developed the Pegasus spyware believed to have been used against the Catalans, has denied it has any role in operating its hacking spyware software and has said it has no knowledge of who its government clients target.