Carmen Calvo, the deputy prime minister taking on Spain’s fascist past, still remembers the first time she saw the monumental complex erected by the late dictator Francisco Franco.

“I saw a place built with forced labour for the glory of a dictator,” she said of that visit four decades ago to the Valley of the Fallen, the divisive site that holds the remains of at least 33,000 of those who died in the 1930s civil war that brought Franco to power. “It gave me a sense of impotence,” she recalled.

Now Calvo wants more action, four and a half decades after Franco died in office.

The Socialist minister is championing legislation that would, among other reforms, step up the exhumation of tens of thousands of bodies that Franco’s troops dumped in pits across the country, establish an authoritative register of victims, and change the Valley itself. The centrepiece of the site 50km north of Madrid is a huge basilica dug into the mountain under a 150m cross with a cupola mosaic featuring a rendition of the fascist Falange flag.

Person holding Franco-era Spanish flag at Valley of the Fallen

The Spanish moves come as countries around the world face a reckoning with their histories, with the UK debating how to confront its slave-trading past and the US grappling with centuries of racial injustice.

Critics say Spain’s leftwing administration is sowing further division in a polarised society, although Calvo, who sees the civil war as part of the broader struggle against fascism, insisted the plans are no more than the country owes itself.

“What do we say to the families?” she said in a Financial Times interview. “We don’t have the right to forget, we have the obligation to remember . . . We have more disappeared than Chile and Argentina together.”

Government officials highlight historians’ estimates that the Franco regime killed some 140,000-150,000 people in military tribunals and extrajudicial murders between 1936 and around 1947. They say 20,000-25,000 may still be recoverable from mass graves over the next four to five years.

Though the ultimately defeated Republican side was also guilty of war crimes they were not at the same scale. “The repression by [Franco’s] rebels was [in terms of deaths] about three times greater than that which took place in the Republican zone,” the historian Sir Paul Preston wrote in his book The Spanish Holocaust.

Carmen Calvo, deputy prime minister

Spain’s government hopes to finalise a draft law in the coming weeks, after which it will be sent to parliament for approval.

But this week top Spanish judges registered concern about some of the proposals, particularly the impact on the right to assembly and freedom of expression, given government plans to close down a foundation dedicated to Franco’s memory. The judges also worried the measures could be “asymmetric”, in favour of Republican victims.

In a recent FT interview, Pablo Casado, leader of the centre-right opposition People’s party, depicted the government’s preoccupations as out-of-sync with contemporary concerns.

“Am I going to talk about Franco?” he asked. “I’m going to talk about the culture war here and now, and the culture war now is not what happened 80 years ago.”

The draft law is the third big move by a Socialist-led government this century to address Franco’s legacy. A 2007 law authorised state financing of the exhumation of mass burial sites and prime minister Pedro Sánchez ordered the removal of Franco’s corpse from the Valley in 2019.

Franco’s coffin moved from the Valley of the Fallen

But the latest measure goes much further than its predecessors.

In particular, it makes the recovery of bodies from mass graves not just the right of the families but the obligation of the state.

The government has already stepped up the pace of disinterrals, which largely halted in 2013, when Spain’s then PP administration defunded the 2007 law, which it regarded as divisive.

This year, the government is financing the exhumation of 114 sites across Spain. Overall, officials estimate up to 600 mass graves remain.

Some sites are small, others enormous. Excavators have uncovered the bodies of more than 450 people shot by Franco’s troops at one site in Seville; it could ultimately yield 1,000. Officials say another site in Cordoba province may contain up to 5,000 bodies.

Human remains at a mass grave in Seville

The law also establishes a national DNA database of victims and plans to update teaching of the civil war period in schools.

Officials acknowledge this is one of the most explosive issues of all. “The state has the obligation for these truths to be part of people’s education,” Calvo said. “How can someone make the political case for people not to know?”

The government has, for now, no plans to disinter all the estimated 12,000 Republican dead taken from mass graves by Franco’s regime and reburied at the Valley together with their former foes. But the legislation recognises families’ rights to retrieve bodies from the site. There are already some 60 requests.

The over 33,000 graves behind the basilica’s chapels would be converted into a civilian cemetery and the body of José Antonio Primo de Rivera, founder of the fascist Falange, would be moved from its privileged place before the altar.

On a recent June day, several visitors to the Valley complained about the government’s plans. “It’s better to leave things as they are than reopen wounds,” said Diego, a security guard who declined to give his surname.

Others thought it right that Spain should confront the most scarring period of its history. “Our grandparents suffered the civil war . . . they thought that afterwards there was a real peace, but now things look different,” said Sol De Mosteyrín Hernández, a teacher.

“We need a profound process of reconciliation in this country — and that is only now beginning.”