Behind cold metal gates stands Blawarthill Parish Church in Glasgow.

It's a modern building, painted white but grimy with rain. Two sticks of wood are nailed to the wall forming a spindly cross which looks as though it could break loose with the next gust of wind.

Inside the Scotstoun church is a tiny room: the Glasgow North West Food Bank. The light is flicked on and chaos is revealed: bags of sugar stacked by the window; blue crates overflowing with tins; rickety shelves packed with boxes. It looks like the closing-down sale at a budget supermarket.

Soon the room fills with volunteers. They sort the donated food from the blue crates, checking the expiry date and making sure the food isn't perishable, then it is categorised and placed on the shelves.

The volunteers endeavour to make sure each parcel has variety - there could be a jar of coffee, tins of soup, some long-life fruit juice, a packet of pasta, some tinned veg, biscuits. They'll even provide toothpaste and shampoo if needed.

The "clients" start to arrive. They have been referred here by doctors, social workers and charities. Space is cleared at a table and a volunteer assesses each person, giving them enough food to last three days. When the formalities are over, they are invited to pop down the corridor to the food bank's café for free toasties and hot drinks.

By now the room is cramped. Volunteers are stepping around one another, crates are being sorted, bags are being packed and a woman is asking if anyone wants tea.

This Scotstoun food bank is open only twice a week, for two hours at a time, so everyone has to be dealt with in that short window, yet there is no stress or temper in this warm room, only frantic activity.

Lorraine is one of the volunteers, and a former client of the food bank.

She says: "I was stuck. I wasn't getting any money and had the housing on my back because the rent wasn't getting paid.

"I asked for a hardship payment but they'd only give me that if I was homeless, so I was asked to put myself out on the street."

Lorraine used the food bank when she had cancer. She entered remission, but then tumours were found in her right kidney. The doctor declared her unfit for work, but the Benefits Agency over-ruled this and her claim for Employment Support Allowance (ESA) was rejected.

She found work as a cleaner but had to quit. Her subsequent claim for Jobseeker's Allowance was denied as adjudicators said she was clearly unfit for work and so must claim ESA - but her ESA application had already been turned down. Welcome to austerity in Scotland, Christmas 2013. Kafka could have invented this world.

Shunted from pillar to post, ill and penniless, Lorraine was left with nothing. "Basically, they kept on giving me the run-around, and I had to wait eight weeks for benefits, during which I was left starving."

She sought other help, including the Community Care Grant, but benefits agency staff said she couldn't get such payments unless she was already receiving other welfare help. More shades of Kafka.

By now, Lorraine had also been diagnosed with heart arrhythmia, high blood pressure, depression and her kidney was inflamed. Add starvation to that mix.

In desperation, she applied for a hardship payment but was refused. Staff told her they only assisted those of "no fixed abode". Their advice? Declare yourself homeless.

Lorraine refused to give in. She says: "I fought and fought and fought so they sent me to get re-assessed. The doctor took one look at me and said she wanted an ambulance because of the state of my legs." By now, Lorraine's dangerously high blood pressure had turned the backs of her legs scarlet and swollen.

She declined the offer of an ambulance as she had borrowed money to buy an all-day bus ticket into the city. "I'm not going to waste it," she told the doctor, and took herself to hospital on the bus.

The doctor also referred Lorraine to the food bank while she waited for a decision on her benefits. It was, quite literally, the only source of help - they welcomed her, fed her, and assisted her with the paperwork to make her benefit claims.

Lorraine finally received the ESA she was due and her cancer is in remission. Feeling stronger, she volunteers at the food bank and will be there on Christmas Day organising a festive dinner for others in need.

She says: "I'll feel rotten if I'm at home and there's people who might not even have a packet of noodles."

Angela will be one of those having Christmas dinner at the food bank. She has been declared unfit to work due to severe anxiety. "I could only hold down jobs for a couple of weeks," she says, and adds that now she has trouble leaving the house.

She has been pushed into near starvation, she says, by the "bedroom tax" - where a claimant's benefit is cut if they live in council or housing association accommodation and the state feels they have a spare room in their home.

The subsequent drop in her benefits has pushed Angela into rent arrears and she is struggling to find money for food. "I've got the bedroom tax plus rent arrears and I just can't cope," she says. "How do they expect folk to survive?"

The bedroom tax and paying her rent arrears means Angela's weekly income has been cut to £62.50 - below the £71.70 which the Government say is the minimum a single person needs to live on.

She is reluctant to use her heating so carries her duvet through the flat with her. "Then there's the cat," she smiles, "he snuggles in." This gives her added warmth.

The bedroom tax has hit her hard and she would gladly move to a one-bedroom flat - the only problem is that, even if one were lying empty next door to her, she would be forbidden from taking it as the council will not permit a house move when rent arrears exist.

The bedroom tax has pushed her into arrears and the very same bedroom tax prevents her from moving. "There's no logic to it," she says. Once again the spirit of Kafka looms large in the system.

So with just a small amount of cash left over each week, Angela is forced to use the food bank. Having been declared unfit for work, her benefits eventually will rise to £112.45 per week - but there is a 13-week waiting period before the money will increase. Until then, the food bank will keep her going.

The use of food banks has increased massively since the Coalition came into power and began its welfare reforms. The Trussell Trust, a Christian charity which helps local communities start up food banks, issued food to 26,000 people in 2008-09 - this year the number was 346,992. In the last 12 months, food bank use has risen by 170%, and 36.3% of those helped were children.

There is scant hope that food bank use will decline. Welfare Minister Lord Freud has urged councils to invest money in food banks, saying it is "absolutely appropriate" that people use them. No wonder opponents of austerity measures say the idea that the welfare state will care for the needy is gradually eroding under the Conservative and Liberal Democrat administration, with the Government simply assuming that good-hearted local people will step in to provide rations for the desperate.

Gill McCormick helps run the Glasgow North West Food Bank. She is endlessly calm and cheerful - but when asked about the Government's attitude towards food bank users, her face darkens. She says: "I don't know where all this negativity has come from. They make it seem as though it's something to ashamed of, but there's a load of people out there who are unable to work and are left feeling like utter failures."

She has little optimism for the immediate future and says people gather in the food bank café and tell her they want to die. The Forget Me Not Café is a vital place, providing a safe haven and community space for the clients.

"An agency will phone and say, 'We have someone here who hasn't eaten for five days. Can we send them along?'" says McCormick, and that was the trigger for setting up the café: it is a support network for the clients, but also a practical way to ensure they can feed someone immediately, before having to go through the paperwork.

Discussing the food bank clients, she sees no resemblance to the stereotypical "scroungers". Instead, she sees a mother who cared for her disabled son before being told she must get a job and that carers would be sent in her place. The lady complied and her carer's allowance was stopped immediately - but she still had to wait a month for her wages to come through, so had to use the food bank to feed herself and her disabled son.

There is a man recovering from surgery who stayed with his mother to recuperate, meaning he wasn't at home to collect letters summoning him to the Benefits Agency. As he missed the appointment, his money was halted as punishment.

Nowhere does McCormick see worthless people who have brought this on themselves.

Her mobile phone rings. It is the Jobcentre in Balloch asking if they can send someone down. They have a woman who has a blood clot on the brain and can't work. Until her benefit money comes through, she'll have nothing.

McCormick spends a lot of time on her phone, speaking to utility companies. Many food bank clients have either had their power disconnected or are on the verge of being cut off. She phones the firms to ask for leniency. "But most of the time they won't even entertain us," she says.

For families without electricity, or those who cannot afford to run the cooker, the food bank volunteers create special food parcels made up of cereals, Pot Noodles, biscuits and powdered soups - foods which can be eaten cold or prepared with a kettle. Yes, she says, children are being brought up on this diet.

A dusty, yellow crate sits by the door, with a skateboard, some books and a stuffed lion inside. They are collecting toys for the children who will be having Christmas dinner at the food bank. McCormick says they will have tinsel and get some sweets and put music on. They are expecting about 100 people.

She smiles, saying she pictures it as The Muppet Christmas Carol. "It'll be like when Scrooge turns good and everyone in the community comes together." Then she gestures to that dusty, yellow crate. "But we need a bit more."

For more information on the ­Trussell Trust's work, or to donate, visit: www.trusselltrust.org