Spain’s supreme court is expected to announce on Tuesday morning whether General Franco’s remains can be exhumed from the vast mausoleum outside Madrid where they have lain since the dictator’s death in 1975.

Removing Franco’s body from its tomb in the Valley of the Fallen has been one of the key priorities of the Spanish Socialist Workers’ party (PSOE) since it came to power in June last year.

PSOE argues the basilica and its 150-metre-high cross are a monument to the Franco regime that glorifies the winners of the civil war rather than commemorating its victims.

“The wounds have been open for many years,” Spanish prime minister, Pedro Sánchez, told parliament 14 months ago. “Too many years. The time has come to close them.”

But the move has been bitterly opposed by the dictator’s family and admirers. In June this year, just days before Franco’s body was due to be dug up, the supreme court ordered the exhumation to be suspended while it considered an appeal from his family and other groups.

Three months on, the court is due to reveal its ruling on whether the government can proceed with the removal of the valley’s most famous occupant.

The hulking monument, which was partly built by captured republicans and political prisoners, is a mass grave containing the remains of more than 30,000 people who fought on both sides of the war.

Although supposedly a memorial to all those killed in the conflict, only two graves are marked: Franco’s and that of José Antonio Primo de Rivera, the founder of the Falangist party.

The Francisco Franco Foundation, which exists to promote and preserve the fascist dictator’s legacy – and which was also part of the legal challenge – is already weighing up its next moves.

“We’re confident in the strength of our arguments,” said the foundation’s president, Juan Chicharro Ortega.

“We’ll have to see what happens but the signs and media leaks may suggest that the supreme court will approve the exhumation order.”

However, Ortega believes that even if the body is exhumed, the move could yet backfire on the PSOE.

It has been suggested that Franco could be reinterred next to his wife in her mausoleum in the Mingorrubio-El Pardo municipal cemetery near Madrid. But the Franco family said that if the body is dug up, it ought to be reburied in the family crypt in the Almudena cathedral, which stands in the centre of the capital.

“Mr Sánchez may win a partial victory by getting the generalísimo out of the Valley of the Fallen, but how’s he going to explain it all if he ends up in the Almudena cathedral of all places?” said Ortega. “It’ll be much easier and closer for people who want to come and lay flowers.”

The Association for the Recovery of Historical Memory (ARMH), which works to find and excavate the bodies of those killed during the civil war and buried in mass graves, says it is high time Franco left the valley.

“It’s not very democratic for a country to spend public money on the upkeep of a dictator’s tomb,” said the association’s president, Emilio Silva. “It’s a perfect metaphor for the impunity of the dictatorship.”

He also pointed out that the tens of thousands of bodies now lying in valley had been “kidnapped” from their original resting places around Spain after the regime decided that the site should house both the nationalist and republican dead and serve as a monument to national reconciliation.

“No government has ever wanted the door of the valley to open so that they can come out of there,” said Silva.

Time, he added, was running out for all those elderly Spaniards who want to retrieve the remains of the relatives they lost in the civil war and rebury them before they themselves die.

Despite all the talk of the wounds of the past, the court’s decision could have a very contemporary impact as Spain prepares for its fourth general election in as many years.

Although the PSOE won the most votes in April’s vote, the party fell short of a majority. Attempts to form a government came to nothing over recent months and another election will be held on 10 November.

“If the court says on Tuesday that they can get him out – and if the government does – that could provoke a certain reaction from the far-right that could mobilise the PSOE vote,” said Silva.

Whatever happens, however, the ARMH doesn’t want to see Franco moved from the valley to Mingorrubio-El Pardo as the cemetery is owned by the state and funded from the public purse.

“If the government allows him to end up in the Almudena cathedral in the middle of Madrid, it’ll be a symptom of political and democratic weakness,”added Silva.

“But what we don’t want is to keep seeing our taxes used to maintain his tomb, which is what’s happened ever since we returned to democracy.”