Frontline charities report that up to 90% of families in the poorest neighbourhoods rely on food banks and soup kitchens. But, with no end to austerity in sight, even the volunteers are flagging

Hunger is not a word that comes easily to Antonis Antakis. And at 28 Veikou Street, in the cramped confines of the Solidarity Club, it is not a word that is ever mentioned. But the fear of not having enough to eat is the force that propels those who stop here – and what keeps the tireless volunteers stacking rice, pasta and other dry goods that Greeks like Antakis take home.

"The truth is, if I didn't come here I wouldn't have the means to feed my children," said the recently widowed father-of-three, his eyes fixed on the floor. "Three years ago, when I was the boss and had two employees, the idea of going anywhere to collect food would have been inconceivable. Back then, I was earning €3,000 (£2,600) a month and the fridge was always full."

The task of ensuring that families like Antakis's are fed throughout the summer became more stark at the weekend as Greeks prepared to take their traditional summer break, affecting the provision of basic services like food distribution to the poor.

Ordinarily, the prospect of the Orthodox church – or any other charitable organisation – scaling back duties in August would have gone unnoticed. But in debt-stricken Greece it is impossible to ignore. Against a backdrop of record unemployment, and with the country ensnared in its worst crisis in modern times, hardship is surfacing in ways that few would ever have foreseen. Hunger and undernourishment are part of that spectre.

For Antakis and the growing number dependent on soup kitchens, who will now be bereft of outside support, August has become the cruellest month.

"I really worry that one day I won't be able to feed my kids at all," lamented the 39-year-old former floor layer turned taxi driver. "From being the boss, I am now lucky if I earn €500 a month. You can't live on that and pay the bills and all your debts and every tax they throw at you, and still survive."

With its dedicated staff and can-do spirit, the Solidarity Club is similar to many other groups established by concerned citizens appalled by austerity's corrosive effects. It is run from, although not backed by, the local branch of the radical leftist opposition party, Syriza.

In a telltale sign of Greece's unravelling social fabric, the Veikou Street headquarters sit not on the decrepit outer edge of a capital entrapped in a sixth year of recession but in its centre, streets away from Athens' most expensive boulevard and within view of the ancient Acropolis.

"I had no idea and was shocked to learn that people in this neighbourhood, on these streets, in all the buildings that I pass every day, were suffering so," said Panaghiota Mourtidou, 54, the organisation's co-founder, busily packing food boxes. "After all, we're talking about the middle class, people who for a long time were too ashamed to admit they had such problems."

Malnourished children eventually gave the secret away amid reports nationwide of pupils fainting in schools. "Teachers were reporting cases of kids who had turned up at school with nothing more than rice or stale rusks for months," Mourtidou recalled. "That's when we decided to work with parents' associations and trace families. Through food collections at the supermarket up the road we now feed around 130 people twice a month."

As the country lurches from one aid handout to the next, a climate of quiet desperation is growing in Greece. The politics of poverty – brought about by the relentless cuts, tax rises and job losses demanded in return for EU and IMF rescue funds – has left wreckage in its wake.

The Greek Orthodox church alone feeds an estimated 55,000 people a day; municipal authorities distribute another 7,000 meals at soup kitchens around Athens. "Normally we wouldn't close but the women volunteers who cook in church kitchens all over Athens need to have a rest," said Father Timotheos, spokesman of the Holy Synod, the church's ruling body.

"At all levels, people are finding it very difficult. Demand for food has gone up extraordinarily," he told the Guardian, conceding that if the needy couldn't travel to the church's central soup kitchen they were likely to face immense difficulty.

Across town in Neos Kosmos, a working-class district where locals are often spotted scavenging for food at the weekly fruit and veg market, Christos Provezis put it more bluntly. "It used to be that one in 10 went to soup kitchens," said the unemployed civil engineer, who started his own solidarity group in the area last year. "Today it's more like nine out of 10.

"They said the crisis would pass in 2012 and now, in 2013, they say we'll see the light at the end of the tunnel in 2014. The truth is, its only getting worse. Greeks have spent their savings, there's no more fat."

In a withering report this year, Unicef estimated that nearly 600,000 children lived under the poverty line in Greece, and more than half that number lacked basic daily nutritional needs. "In poorer families we are seeing an inability to cope with children's health, social and educational needs," said Lambros Kanellopoulos, who heads Unicef's Greek branch. "Social exclusion is growing. I am seeing it in the middle class where incomes have been hard hit by all the cuts."

In Greece's increasingly tense political environment the politics of food is delicate. In recent months the unapologetically far-right Golden Dawn party has turned to staging "Greek only" food handouts as a means of winning support.

The politicking has helped cloud what many fear could be the makings of a humanitarian crisis in the coming months. Like malnutrition – the most pernicious byproduct of austerity to date – homelessness is also on the rise. "It's going to get worse before it gets better," said Xenia Papastavrou, who runs the country's pre-eminent food rescue organisation, Boroume.

"Social services in municipalities can't keep up recording the sheer numbers of those in need," said Papastavrou, whose programme distributes surplus food donated by chain stores, restaurants, bakeries and hotels to 700 soup kitchens across Greece.

"In traditional middle class neighbourhoods like Zographou the number of those requiring support has gone up from 50 to 500 since 2011. Everywhere we go it's the same story, which is why we need all the help we can get."