Laura Sánchez never met her great uncle, Ramón Acosta. But she is proud to point out that he was a war hero. Acosta rescued three soldiers from his crashed helicopter after it was shot down in flames 30 years ago by a British Sea Harrier jet during the Falklands War. "Right now we are surrounded and it will be whatever God and the Virgin want it to be," Acosta wrote in his last letter home. He went missing in action shortly afterwards on 11 June 1982, somewhere near Mount Kent on East Falkland, just three days before the war ended. In his native town of Jesús María in the province of Córdoba, there is a street that bears his name.

So you would expect 29-year-old Sánchez to be a staunch Malvinera, which is what diehard supporters of Argentina's claim on the Falklands, known to Argentinians as Las Malvinas, call themselves. But you'd be wrong.

"When I was a kid I couldn't figure out why he died," says Sánchez. "And I couldn't understand why at school they taught us that the people over there are Argentinians."

Sánchez became even more perplexed after her grandfather returned from a visit to his brother's symbolic resting place in the Argentinian cemetery on the Falklands, where 237 Argentinian war casualties are buried, close to the location of the Battle of Goose Green. "My grandfather came back feeling like he'd been to Britain; it wasn't like Argentina at all."

Sánchez, a fan of Alanis Morissette and Lord of the Rings and a bespectacled student of history at the University of Buenos Aires, represents a small but growing number of youngsters born after the 1982 war who are questioning the old slogan "Las Malvinas son Argentinas" ("The Malvinas are Argentinian"), emblazoned on the placards that greet foreigners arriving at practically every airport and border crossing.

"Sometimes, I'm afraid of saying it, I'm afraid of how people will react, but why are they Argentinian? And why, for that matter, should they be British? Don't they have the right to self-determination?" she asks.

That kind of talk can get you into serious trouble, not to mention angry dinner-table arguments in Argentina today. On Wednesday, angry protesters from the leftwing Peronist "Movimiento Evita" group gathered to yell "British out of Malvinas" at the doorstep of the British ambassador's residence in Buenos Aires. The stately mansion, perched atop one of the few low hills on this otherwise flat capital, in an exclusive few blocks of prime real estate known appropriately enough as "La Isla" ("The Island"), had grown unaccustomed to these once periodic outbursts of patriotic fervour.

But this new march came on the crest of a worrying escalation of verbal crossfire and political point-scoring between Argentina and Great Britain as the 30th anniversary of the Argentine invasion of the islands approaches in April. In recent months, the government of President Cristina Fernández, herself an avowed Malvinera, has made the sovereignty question again a main policy objective.

In an unprecedented step, Argentina managed to rally the support of its closest South American neighbours including Brazil, a new world heavyweight. The Mercosur trading group has put in place a co-ordinated ban against ships flying the Falklands flag docking at their ports.

By threatening at the same time to ban the weekly planes of the Chilean airline LAN from flying through Argentine airspace on the only commercial flight that reaches Port Stanley, Argentina has taken a bold step towards pressing its sovereignty claim by isolating the islands from the South American mainland.

But among young people in a country where voters aged between 20 and 35 make up 25% of the population, there is distinct evidence that the cause of the Malvinas is not a top priority.

The School of Philosophy and Literature at the University of Buenos Aires is a dilapidated old building in the middle-class neighbourhood of Caballito that used to be a cigarette factory. It is a hive of political activity that sets the tone for much of the student activism in Argentina today. Its old walls are adorned with banners and posters of Che Guevara, Eva Perón, Fidel Castro, even Mao Zedong.

"I don't know if it makes sense to reclaim a territory whose population doesn't want that," says Nicolás Ferraro, a student who was born in 1981, just a few months before the invasion. "Even if we were able to regain sovereignty, the islands should have at least a strong autonomy."

A fellow student, Catalina Flexer, dismisses the current friction between the two countries as political fireworks. "It's only the government talking about the Malvinas. People are thinking about other things. The whole business about denying access to South American ports to ships flying the Falklands flag is a big lie," Flexer says. "Everybody knows that all they have to do is change the Falklands flag for a British flag and then they can sail into port without any problem."

But it is young Argentinians who have been to the islands themselves who best embody the dramatic turnabout. The eye-opener for 30-year-old documentary producer Tamara Florin was a trip to the Falklands to film a television special about life on the islands. The documentary, So Near, So Far, was the first to offer an alternative to the official story about the Malvinas to the Argentinian public.

"It changed me completely to be there," says Florin. "I was born in 1981, so I have no memories of the war."

As soon as Florin landed, she realised all her preconceptions were mistaken. "There is nothing Argentinian about the islands. The people eat fish and chips, they have dinner at 6pm, they're British. The only thing that is remotely Argentinian is maybe the landscape that resembles barren Patagonia and the thousands of still active landmines that the Argentinian forces left behind."

Florin says she tries not to express her new point of view among fellow Argentinians. "I know it is totally politically incorrect to speak this way in Argentina and when I do, even among people my age, the response can be stony silence."

The most outspoken opponent of old hardline thinking on the Malvinas is Jorge Lanata, a 51-year-old chain-smoking journalist famous for confronting sacred cows and uncovering corruption. He was the presenter of the documentary that Florin produced five years ago.

"Argentina's policy towards the Malvinas is insane, erratic, senseless," says Lanata. Each morning you can find him sipping coffee and smoking at a corner cafe on the wide, tree-lined Libertador avenue that cuts through the city's well-to-do north side.

"Blocking the ports is more of the same madness," Lanata says. "Argentina needs to integrate the islands, not isolate them. We have to face up to the fact that we lost the war. Malvinas is not part of Argentina; it is part of our imagination. We're so blinded by years of rhetoric that we can't see reality."

Lanata believes that the revival of the sovereignty claim is a smokescreen for the belt-tightening the government is having to enforce after almost nine years of uninterrupted growth. "It's no coincidence, this is the first time in history that a Peronist government has had to put austerity measures in place – they don't know how to do it."

Sánchez agrees: "I fear that all this is just nationalist propaganda to cover up real problems like poverty."

Another highly respected thinker, Beatriz Sarlo, holds similar views. This 70-year-old former Marxist who now pens hard-hitting columns for the conservative daily La Nación bravely defines herself as an "anti-Malvinera". She disagrees with the government line that the 1982 invasion was an isolated incident masterminded by a few crazy generals.

"The dictatorship's move was supported by wide majorities," Sarlo wrote in a recent column, in which she claimed there was a taboo regarding real support for the war among the majority of Argentinians, including its civilian politicians. "It can't all be blamed on the military. Argentinian society needs to review its history of frenetic enthusiasm."

Although it is certainly far-fetched to believe the Argentinian government would ever seriously consider Falklanders as equal negotiators, it is clear that every day an increasing number of young Argentinians would not consider it unreasonable.

"How can it be that nobody had ever stopped to consider the wishes of the people on the islands?" asks Florin. "They're not Argentinians. They're British.

"In Argentina, nobody ever talks about who they really are and how they might feel."