A woman who committed suicide left a note blaming the Government's so-called bedroom tax for her death.
Stephanie Bottrill, who killed herself earlier this month, wrote in her final letter: "I don't [blame] anyone for me death expect [sic] the government."
Her son Steven, 27, said she was struggling to cope after being told to pay £20-a-week extra for two under-occupied bedrooms at her home in Solihull.
He told the Sunday People: "I couldn't believe it. She said not to blame ourselves, it was the Government and what they were doing that caused her to do it.
"She was fine before this bedroom tax. It was dreamt up in London, by people living in offices and big houses. They have no idea the effect it has on people like my mum."
Ms Bottrill died 10 days ago. She was 53.
In the days running up to her death she had told neighbours: "I can't afford to live any more."
Describing her case as a "tragedy", shadow chancellor Ed Balls told Sky News' Murnaghan programme the bedroom tax was "driving people to the edge of despair in their many thousands across the country".
Solihull Council Labour group leader David Jamieson, who knows the family, said: "I'm absolutely appalled this poor lady has taken her own life because she was worried how she would pay the bedroom tax.
"I hope the Government will sit up and take notice and reconsider this policy."
The bedroom tax means people of a working age in social housing who have a spare bedroom will find housing benefit claims reduced by £40 to £80 a month.
Ms Bottrill had lived in her £320-a-month home for 18 years as she raised her son and daughter, but she could not cope with the extra £80 she had to find every month.
Mr Bottrill said his mother wanted to work, but there was no way she could.
As a child she was diagnosed with the auto-immune system deficiency, Myasthenia gravis.
The illness made her weak and she had to take constant medication.
Doctors had told her she was too ill to hold down a job, but she had never been registered as disabled, so she lived without disability benefit.
Neighbour Rosie Hough, who used to see Ms Bottrill every day, told Sky News: "She did say some things about her problems about the rent and that, and having to find the extra money and that but I would have never have said that she was a woman who would take her own life.
"It's absolutely shocked the whole street. We just can't comprehend that she has gone."
Brian McCann, who lives a few doors away from Ms Bottrill's home, said: "We knew that the tax had affected her because the girls had all chatted in the street and she was really worried about it."
Sky's Political Correspondent Sophy Ridge said: "Downing Street isn't commenting on what it says is a personal matter but clearly this will lead to calls for the policy to be changed.
"Downing Street knows it is controversial. That's why some amendments have been made to the policy already, saying armed services personnel and foster carers won't be affected.
"Iain Duncan Smith, the Work and Pensions Secretary, has argued consistently that he thinks this policy is a fair one, but certainly I think this row is going to keep going."
The Samaritans said that "although a catalyst may appear to be obvious, suicide is never the result of a single factor or event and is likely to have several inter-related causes".
:: Anyone feeling emotionally distressed or suicidal can call the Samaritans on 08457 90 90 90 or CALM on 0800 58 58 58.