Seventy years ago Manolis Glezos scaled the walls of the Acropolis to tear down the swastika, hoisted over the monument that Hitler had triumphantly described as a symbol of "human culture". This single act of defiance – the first direct action against Nazi rule in Greece – would go on to cast the headstrong young man as one of the country's greatest defenders of democracy.

Today the enemy may have changed, but at nearly 89, Glezos is still fighting. For many Greeks he has become a symbol of resistance in another, very different sort of war: one that has pitted the near-bankrupt country against the forces of world capitalism and thrown it into an unprecedented struggle for its economic survival.

In the midst of Athens' worst crisis in modern times, Glezos says he never thought he would see Greece come to this. "Not since the German occupation have we been in such a difficult and dangerous situation," he laments, with an angry thump of his hand.

"Economically, democratically, the Greek people are seeing hard-won rights being wiped away. Unemployment is growing, shops are closing daily and decisions that are totally unconstitutional are being made."

Popular icon, protester par excellence, Glezos does not require much to goad him into action. The veteran leftwinger is a force in the civil disobedience movement shaking Greece.

As a proponent of direct democracy, the campaign that has propelled thousands of Greeks to protest against the austerity measures meted out to rein in the country's runaway debt, demand for Glezos to be on the frontline at demonstrations is at an all-time high.

"People are not going to back down. They are very conscious of what they want," he says, seated before a desk in the book-lined study of his Athenian home. "The summer may be here but I've been very busy attending neighbourhood assemblies to discuss what our future tactics might be."

In March last year pictures of the wiry, white-haired activist being teargassed by a riot policeman outside the Greek parliament sent a tremor through Europe's nascent anti-austerity movement. But, though appalled by the harshness with which rallies have often been crushed, Glezos reserves his greatest criticism for the attitude of Germany and Britain towards Greece. Both countries, he insists, stand guilty of "enormous ingratitude".

"Germany today lives not under Nazi rule but in a state of freedom and that it owes in great part to the struggle of the Greek people," he said, referring to Hitler's disastrous decision to postpone the invasion of the Soviet Union as a result of the unexpected resistance encountered in Greece. "Then there is the issue of food. If German people are alive it is because Greek people died."

Glezos has not forgotten the howls of the starving or the images of municipal carts carrying the corpses of those who, during the Nazi occupation, collapsed begging for food in the streets of Athens.

He knows not only because he was there; he counted them.

"I worked in the statistics office of the International Red Cross and every day I would note the deaths of around 400 people as a result of famine. We lost 13.5% of our population, more than any other occupied country, because all of our foodstuffs, our crops, were requisitioned [by the Wehrmacht]. For those two reasons alone Germany should help Greece."

Throughout the war "little Greece" had stood alongside the Allied forces. "Who came to England's help? Who was behind the first victory against the Axis [powers]?" he asked, conjuring the Greeks' defeat of Mussolini's forces on the Albanian front in 1940. "Who did Churchill so famously say fought like heroes? Britain should have tried and helped Greece at this difficult moment. Its behaviour should have been different."

Glezos, who would subsequently spend nearly two decades in prison – often in solitary confinement — as Greece slipped into civil war and then years of authoritarian rightwing rule, backs up his argument with figures.

It wasn't just the famine and the thousands killed in reprisals as a result of mass resistance, or the eradication of virtually all of Greece's once vibrant Jewish community or the destruction of the countryside. It was, he says, the other indignities suffered by Greece under Hitler. The pillaging of archaeological treasures, the plundering of factories and homes, the looting of national resources, the crippling of the Greek economy – following the Nazis' deliberate circulation of counterfeit Deutschmarks – offences that were all part of what Churchill would go on to call the "long night of barbarism" and from which it has yet to recover.

"To this day, Greece remains the only country in Europe that never received reparations from Germany," added the former MP, who has long headed the National Council for the Reclamation of German Debt. "We never got back any of the antiquities that they took, or the buildings that they seized, or the tons of silver and nickel that they stole.

"If you take into account the enforced occupation loan, I estimate that they owe us around €162bn, plus interest."

Glezos, who has proposed that Berlin fund companies in Greece and scholarships for students bound for Germany by way of compensation, insists he is neither motivated by hatred nor revenge. He has many German friends and every year, he says, they descend on Athens to "try and right the wrong" by demonstrating outside the German embassy. But he is infuriated that Greeks are invariably typecast by the German media as lazy laggards when studies show them working the longest hours in Europe. "The latest agreement to save Greece is all about saving banks and financial capital, not people," he says. "After the war, we won our freedom but we emerged as vassals, first of the English and then the Americans. Being indebted in this way keeps us in that subordinate role. Our new masters are the troika [the EU, IMF and ECB] and they have to go. Mark my words, the Greeks will play a pivotal role in resisting the policies they want to impose."