The former president of the motorsport’s governing body FIA died at home in Chelsea, west London, last May, aged 81.
The inquest heard that he was told he had just “weeks” to live, and that chronic bladder and bowel pain would only lessen with palliative care but could not be cured.
Mr Mosley told his personal assistant of 20 years he was going to take his own life the day before he did so, the inquest also heard.
His PA Henry Alexander said he had gone over at Mr Mosley’s request about 3pm the day before.
He said: “He was sat in an armchair in a despairing way. He spoke to me and said I’d been amazing and thanking me.
“He said he’d had enough, had intentions of killing himself. I begged him to reconsider and said, ‘please, there must be another way’.
“He said he’d made up his mind. When I pleaded with him, asked him if he could give it 24 hours, he said ‘why?’”
A neighbour and his housekeeper called 999 after they discovered a note on his bedroom door, stating “do not enter, call the police”, the remote inquest attended by witnesses and family heard.
A suicide note found on his bedside table was barely legible, due to the large amounts of blood, but the few words officers could make out were “I had no choice”, Westminster Coroner’s Court heard.
Senior coroner Dr Fiona Wilcox said: “On May 24, 2021, police were called to the address of Mr Mosely, attended, and found him lying on his bed with a gun in the vicinity.
“He suffered significant injuries consistent with gunshot wound.”
Mr Alexander, who lived near Mr Mosley, said he had accessed the house through the housekeeper’s basement flat after 8am following concerning text messages the night before.
He said he had spoken to Mr Mosley who said he was concerned about his upcoming cancer operation.
In a written statement, he said: “I sent him a text at around quarter to asking if he would want his breakfast upstairs. I rang him and it went to voicemail.”
DC Ben Benlounes, who gave evidence at the hearing, said he arrived at the scene at approximately 10.15am and spoke with the acting inspector.
The officer confirmed there were no signs of anything suspicious or forced entry.
The inquest also heard a written statement from Dr Christopher McNamara, a consultant haematologist who first saw Mr Mosley in October 2019.
He said the former Formula One boss had been diagnosed with a high-grade lymphoma and that he had recommended a course of chemotherapy for prostate cancer.
Dr McNamara explained that Mr Mosley had a range of different treatments, some of which he took against his medical advice.
“Mr Mosley arrived at a point at the beginning of April when there was a shift away from treating aggressively and more towards controlling the disease and quality of life. I referred Mr Mosley to palliative care colleagues,” Dr McNamara said.
He added: “Max had a terminal illness and accepted this would not be cured.”
As a result of treatment, Mr Mosley developed a fistula – an abnormal passage connecting two organs – which left him “extremely upset” as his quality of life reduced, Dr McNamara told the inquest.
“Mr Mosley had expressed ideas of committing suicide to myself and other colleagues and had been referred to appropriate colleagues. He never expressed a plan of doing this and always said the problem was that his wife would not accept this,” Dr McNamara said.
“He also indicated his affairs had been in order.”
Dr Rasha Al-Qurainy, who led his palliative care, however, said that Mr Mosley never discussed any suicidal thoughts. Giving evidence, he described Mr Mosley as “talkative and pleasant”.
“On the contrary, he said he had plans to renovate the home in Gloucestershire, he was still seeking treatment possibly in the US, possibly in the UK, and others matters that he told me that he had plans to engage in,” Dr Al-Qurainy.
Senior coroner Dr Fiona Wilcox returned a conclusion of suicide at the end of the inquest.
Emma Mosley, Mr Mosley’s daughter-in-law, paid tribute to him in a written statement.
“Mr Mosley died after a long battle with cancer,” Ms Mosley said. “He was a barrister and amateur racing car driver.
“Mr Moslely identified his major achievement as FIA president, the promotion of road safety by the European New Car Assessment programme and the increased safety and the use of green technologies in Formula One.”
Mr Mosley, a qualified barrister, also backed calls for stricter controls of the media after the News of the World published photos and video of him at a sadomasochistic orgy with five prostitutes in 2008.
In 2018, it was alleged he published a racist campaign leaflet in support of his father’s Union movement in a 1961 by-election which linked non-white immigrants with diseases such as tuberculosis, VD and leprosy.
Mr Mosley said he did not “recognise” the leaflet and it was “not something I would have ever wished to be associated with.
His parents – Sir Oswald and Lady Diana Mosley – had a wedding attended by Hitler at the home of Nazi propaganda chief Joseph Goebbels.
Mr Mosley’s parents were both jailed shortly after he was born for being Nazi sympathisers during the Second World War.
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