Vanessa Redgrave paid a personal tribute to NHS staff who saved her life after she suffered a heart attack last year and cared for her sick father and brother towards the end of their lives.
The actress, 79, has been hit by personal tragedy many times. Her daughter Natasha Richardson died in 2009 aged 45 after a skiing accident, and the following year she lost her brother Corin and sister Lynn to cancer.
Last April Mrs Redgrave had to be rushed to hospital after suffering a heart attack while she was alone in her flat in Chiswick, west London.
Addressing crowds at a rally in central London to support junior doctors in their dispute with the Government, she said: "My life was saved at the end of April last year by NHS consultants, NHS junior doctors and nurses in Hammersmith Hospital, thank you."
She said NHS doctors and nurses had provided her family with care and compassion in hospital, but they were being overstretched and under-resourced.
And she told the crowd that her father, the great actor Sir Michael Redgrave who died in 1985 after suffering from Parkinson's disease for 12 years, had his care undermined by Margaret Thatcher's government.
She said: "My father died aged 70 in 1985. The hospital doctors told me and my brother that they'd got rid of the trouble he was in hospital for - Parkinson's disease had blocked his bowels.
"But they said next time it gets blocked don't bring him back, we haven't got enough beds.
"That was Mrs Thatcher's government, and my father was just one of the fathers."
Recalling her brother's care, she added: "My brother had a cardiac arrest in 2005, that meant short term memory loss. That meant that he could read, he was still a wonderful person, but he couldn't act anymore."
She said he needed support for his mental health, but this is "at the bottom of the rung of the whole system which this Government leads".
Mrs Redgrave added: "He was given some help freely, under the counter as it were, by an NHS consultant who kept his spirits up because the NHS psychiatric consultant knew what Corin needed.
"But my brother didn't get everything he needed. He did get 10 weeks and that was all that was allowed.
"She was great, but she could only give 10 weeks and she was in such a rush with the workload she'd got she could hardly speak a straight sentence.
"I thank her for what she put in for my brother, but I know what overwork means, as you do."
Several hundred demonstrators gathered at the rally, which comes ahead of a 24-hour walkout due to begin on Wednesday, when junior doctors will provide emergency care only from 8am.
Mrs Redgrave was joined at the rally by her friend and fellow long term political activist Dame Vivienne Westwood.
The fashion designer told the crowd: "Junior doctors are the future and you will win. You are fighting to protect the National Health Service, the NHS. To protect it from Government cuts.
"We need more doctors not less doctors. Doctors who get enough sleep so they can give their best care to patients."