Chancellor George Osborne's shamed psychiatrist brother showed "a blatant disregard for the fundamental tenets of the medical profession" in having a two-year sexual relationship with a vulnerable patient.
Dr Adam Osborne was struck off from the medical register after the Medical Practitioners Tribunal Service (MPTS) ruled that his fitness to practise was impaired by reason of misconduct.
MPTS panel chairman Dr Nigel Callaghan said that the married doctor's affair with the patient, who he had been treating for depression, anxiety and chronic fatigue, was "profoundly unacceptable".
The woman, referred to as Patient A, went on to make an attempt on her own life two days after Dr Osborne ended the relationship via email.
Despite knowing of her fragile state and suicide attempt, he bombarded her with threatening emails over a 10-day period begging her to retract her complaint to the General Medical Council (GMC) detailing the affair.
The tribunal sitting in Manchester imposed an immediate order of suspension from the register and determined that Dr Osborne's name should be erased from the medical register.
The tribunal was told that following the split in February last year, the woman told him: "I'm very much balancing on the edge and it's so easy for me to tip over just now."
He later pleaded to her: "You still have the power to tell the GMC that you made this up because you were angry at me for discontinuing therapy or that you were confused, paranoid, deluded - whatever excuse you can think of."
He threatened her: "If I get into trouble for this then I will never forgive you for this and I will make sure you pay."
Another email read: "Please don't do this to me, it will destroy me and my family in public."
Dr Callaghan said: "His behaviour towards Patient A has caused her harm and the tribunal could not be satisfied that there would be no repetition of this misconduct."
Dr Osborn had treated the woman at a private practice in central London from February 2011 until late 2014.
In a statement after the hearing Dr Osborne, who is five years younger than his brother, said: "It was never my intention to hurt anyone although I can now clearly see that my irresponsible behaviour has led to a great deal of distress to the people that I care about, in particular my family and the patient in question.
"I realise that there is never any justification for breaking the boundaries of established good medical practice in regards to the doctor patient relationship, and it is never in the best interests of the patient to do so.
"I have found medicine to be a very rewarding and fulfilling career and I am very saddened that this career is now inevitably over."
Dr Osborne, who had admitted the allegations, said he fully accepted the findings of the Fitness to Practise Panel.
In 2010 he was suspended from practising medicine for six months after writing fraudulent prescriptions for a girlfriend, a family member and an escort girl whilst a psychiatry trainee at Wythenshawe Hospital in Manchester.
The Tribunal said that this had been a further aggregating factor in the case.