A victim of the Windrush scandal was failed by the government right up until the moment she died, the Labour MP Margaret Hodge has said.

In a powerful letter to the home secretary, Sajid Javid, Hodge said she was “deeply disappointed” in how her constituent Sarah O’Connor had been treated before her death earlier this month.

She said that the compensation and extra support O’Connor needed after the Home Office’s failings was not offered, leaving it up to Hodge’s office to step in.

“As a Windrush victim, Sarah was treated appallingly by the Home Office who questioned her status as a British citizen for a year. This resulted in her falling into extreme financial hardship, which impacted on her mental wellbeing right up until the day she died,” wrote Hodge, the MP for Barking.

O’Connor was unable to work or claim benefits and her landlord had told her he was going to evict her. The Labour MP said she had personally written to the Home Office about compensation, asking when payments would be due, but was told that where additional support was needed measures had been put in place.

“It fell on my office team … to provide Sarah with extra support,” Hodge said. She argued that Javid had promised to do right by the Windrush generation but that O’Connor would never be reimbursed, leaving behind a “devastated” family.

She added: “I am deeply angry at how the Home Office treated her and will not stop until her family are fully compensated.”

Hodge described the 57-year-old Windrush victim as a remarkable person. “She came to Britain when she was six. She attended primary school and secondary school here, worked, married and raised four children over 51 years,” she wrote.

In March, O’Connor told the Guardian she was facing bankruptcy as a result of being classified as an illegal immigrant. At the start of this year, she said she was so worried about her situation that she was too frightened to open the front door for fear it might be the Home Office coming to to deport her.

She moved to Britain 51 years ago, but had struggled to make officials understand she was in the country legally. O’Connor spent the final year of her life unable to get a job and was refused benefits. She tried to get herself out of the situation and was naturalised in July. Despite this, her problems continued and in the weeks before she died, her landlord had given her notice to leave. She was still struggling to get work and find a new home.

Stephanie O’Connor, Sarah’s daughter, said the immigration problems her mother faced had a huge impact on her. Her mother had been “very bubbly” before that, she said.

“It made her very unhappy. I saw a complete change in her … She wasn’t the same mum any more. She felt like she wasn’t getting anywhere, and she was deflated. I was trying to keep her upbeat; she said she just wanted to give up,” her daughter added.

A GoFundMe appeal has been launched to pay for her funeral.

Earlier this month MPs gave details of Windrush constituents who were still suffering from the scandal’s fallout. One MP complained that benefits were still being withheld from a constituent and another spoke of “intolerable delays” in the task force’s decision-making process.

Oliver Hutchinson, 63, told the Guardian he was still staying with family while he waits for his biometric residence card to be issued, despite having raised his case with the Home Office in May.

The government last month launched a call for evidence to inform its lessons learned review. A consultation is due to run until October on the compensation scheme.

Hodge wrote: “You said the purpose of the compensation scheme is to reimburse members of the Windrush generation … for the losses they have suffered … Sadly Sarah will never be reimbursed.”

A Home Office spokesperson said: “Our sincere condolences are with Ms O’Connor’s family and friends at this difficult time.”