More than 2 million people have used credit cards to pay their mortgage or rent, an increase of almost 50% in a year, according to the housing and homelessness charity Shelter.

Research for Shelter conducted in August found that 6% of the 2,200 questioned had used credit cards to meet their housing costs in the previous 12 months. This compares to 4% in November 2009, and suggests a national figure of more than 2 million people who are making desperate last attempts to keep a roof over their heads.

With an increased threat of unemployment and rising interest rates, the charity warns that many people will be starting the new year with the threat of homelessness hanging over them once they have exhausted the limited and expensive credit available to them through cards.

Campbell Robb, chief executive of Shelter, said: "This research brings into sharp focus how keeping a roof over their head has become a daily struggle for millions across the country. This is a totally unsustainable situation and one which we fear could see thousands more families pushed into the spiral of debt, eviction or repossession and ultimately homelessness.

"Using credit cards to pay the rent or mortgage is simply robbing Peter to pay Paul. With the average credit card interest rate now standing at over 16% it is the worst possible course of action. Already someone faces the nightmare of losing their home every two minutes, and we would urge every single one of these people now relying on credit to keep their home to seek advice urgently."

Shelter has a network of advice services across the country which provide free advice on debt and housing issues, as well as a comprehensive advice website at shelter.org.uk/debt.

Kingsley's story

Kingsley is a self-employed electrician and father of four, and has been struggling to meet payments on a second loan secured on his family's home since his business slowed down with the recession. He used his credit card to pay December's instalment.

"I'm under no illusion that I could lose my home. I had a choice of making a late payment or using the credit card to pay the mortgage so I chose the latter.

"Last month I was doing a job, which I can finish within one month and which pays me £3,000. I am thinking that this month I'll have the money to pay the credit card, pay the mortgage of £368 a month and won't have a lot at the end of it. I'm hoping that next week I get a call for someone I priced a job for that will be £20,000 worth of work.

"If that comes off, I'll be OK until April; if it doesn't then I don't want to think about the consequences."

He is now considering declaring bankruptcy and starting again.

Wendy's story

"I had eight credit cards. I'm 51-years-old and am not daft. I never used my cards in the past, never had any financial problems whatsoever and have always had a perfect credit record. I'm a civil servant, have a responsible job and always maintained my outgoings.

"I'm also a single mum and have been for a while – my problems started when my daughter's father reduced his maintenance and I had a series of health conditions that necessitated me reducing my hours at work. I didn't want to but I had to.

"I also went through a very bad divorce which left me with legal bills of £12,000-£15,000, which was a horrendous amount for a single parent.

"My daughter was undergoing psychiatric help because of abuse she had suffered and I wanted to preserve her continuity of life by keeping the same house. So I fought very hard at the time of my divorce to keep the house. It's only a three-bed semi – not a mansion.

"In order to take the house over I had to prove I could pay the mortgage, but I ended up having to get a £43,000 secured loan on top of my mortgage to pay off solicitors fees, money I'd borrowed from my father and to make up the shortfall to pay off the joint mortgage.

"I had to pay £416 each month for my mortgage with RBS and a £627 payment for a secured loan with NatWest. I fought very hard for that loan and don't blame NatWest for giving me the loan: it was before my daughter's father decreased his maintenance and before I reduced my work hours. At the time I could afford it. It was uncomfortable but I was prepared to put up with six or seven years of hardship to maintain the house and the stability in our lives.

"But there was no flexibility and very soon I started to run into problems. I had a growing child, my boiler went wrong which cost £1,500. It got to the stage where the car insurance was due again and other bills accrued.

"So in the past seven or eight months I started to rely on drawing cash from my credit cards and paying it into my bank account, or phoning up and paying the mortgage by card over the phone. I was also paying for clothes for my daughter on credit card.

"You get in the habit of going to the card and thinking 'when things get better I'll be able to pay it off'. But it's the increase in the monthly payments. I was paying £300 a month towards all my credit cards. I haven't been on holiday, bought lavish clothes or a car.

"My secured loan, mortgage and credit cards come to £1,350 a month and I earn £2,000 a month with everything. It's unsustainable. I have a 12-year-old daughter, a house to run, food to buy. I don't have any money left over at the end of the month.

"Two years ago my credit card balances were zero. I managed to pay them off by partially retiring at work but now I owe £14,000 again. Until November all of my mortgage payments were also up to date.

"I can't do overtime because of medical problems, and my pay has been frozen because of the civil service pay freeze. My daughter's father lost his job so has stopped paying the £300 maintenance.

"I contacted the credit card companies in October but the majority have never replied. I made an offer to pay 40% of my regular monthly payments for a year to allow me to get back on my feet, and I'm making those payments without their agreement. The stress of it all makes me feel ill. I do worry about it and it's not something I take lightly. I don't want anything that wipes the debt. It's my debt and I want to honour it. It's just that my circumstances at the moment mean I can't.

"I would never ever again have a credit card even if I was offered one. It eases your immediate problems but creates greater problems in long run."