Debbie Purdy & Omar Puente: A matter of love and death

This is a love story. An Englishwoman with a taste for adventure meets a Cuban musician in a bar in Singapore. She likes the sound of his violin; he likes the way she fills her little black dress. They fall for each other, and vow to stay together, for better or worse. She helps him survive as a jazz virtuoso; he helps her endure the onset of multiple sclerosis, the degenerative disease that takes away her ability to walk, then slowly begins to shut down her whole body. And then? Well, that depends on what happens in the Court of Appeal.

If things go the way Debbie Purdy wants in a hearing there on Tuesday, she and Omar Puente may have years left together. If not, their love story will end prematurely. Soon. "If the law is not clarified," she says, "I will have to die early."

She means she will travel alone to a clinic in Switzerland, take a lethal draught of barbiturates and die. She would rather not do that. She would rather wait as long as possible, until her pain becomes unbearable and her life unendurable – if indeed that ever happens – then end it in a Swiss bed, holding Omar's hand. But this determined 45-year-old woman absolutely refuses to take the risk that her husband will go to prison for helping her. "The pain that I would suffer at the prospect of Omar being prosecuted would be worse than dying early."

It is illegal to aid a suicide, but the Director of Public Prosecutions has yet to bring a case against anyone involved with the 100 or so Britons who have died at the Dignitas clinic in Zurich. Last month, he said there was enough evidence to convict the parents of Daniel James – a 23-year-old who had become tetraplegic as a result of a rugby scrum collapse – but that it was not in the public interest to haul them before the courts. Debbie Purdy was not reassured. She wants the DPP to state his policy in advance, rather than judging every case after the death. "All I want is for the law to be clarified; then I can make sure Omar never crosses the line. If they say he cannot accompany me, then it means I have to go now, while I am still physically able to do so."

Why is she so desperate to protect him? "It does worry me that he's a foreigner, he's black, he's got a name like Omar. I wouldn't be there to argue on his behalf. English is my first language. It isn't his. Those are not things I want to think about, and worry about."

She discusses this unemotionally, as if making the travel arrangements for Omar to go on tour with his regular employer, the British jazz musician Courtney Pine. But it is disturbing to hear such frank talk of death from a woman who is still – there is no other way to say this – full of life. "Her body is in a wheelchair," says her husband in a deep growl, "but her mind? Ding." He makes the sound of a bell ringing, and laughs.

Fourteen years after their first meeting, Debbie Purdy and Omar Puente are still deeply into each other. You can tell that by the way he reaches across to take a beaker of water from her trembling hands, and by the way she orders him about, playfully. "My tongue still works," she says. "Of course," he growls back, in a deep voice. "If not? Disaster."

They met in January 1995, while she was writing music reviews. Raised in London, she had become a globetrotter in pursuit of thrills: diving from planes or under the water, white water rafting, whatever was going. Born in revolutionary Cuba in 1961, Omar had studied at the island's best music schools. He was developing a reputation that would see him play with Jools Holland and Kirsty MacColl. "I was sent to cover his band," she says. "He was told to be nice to me."

Omar has a different version. "She was all over me. She was dressed in black. She looked stunning, man. She had a massive bum. What? I thought: 'I gotta do my very best to get her.'"

Debbie laughs and scowls at him for saying that: "I spent my life trying to hide my bottom and suddenly I meet a man who thinks it's my best feature."

She was already using a stick, having had some difficulty walking, but it was two months later that a neurologist back in England said that she had MS. Ringing Omar in tears, she said she was flying back to Singapore. She didn't say when. He met every flight from England, until she finally turned up. "It was very sweet." Three years later, they were married.

"I'm not sure we'd have stayed together if I hadn't had MS," she says. "You need a visa to go to the bathroom when you're travelling on a Cuban passport. I'm not sure he would have accepted help from me, being a Cuban musician, if I hadn't needed help from him, being disabled. It was that equality that meant we could have a relationship."

They wanted a child, and tried IVF five times without success. He could have walked away. "Of course, I had the choice," he says. "Every day. It's my decision. I love the woman. That one. There are a million out there, but I choose to be with her. Fool."

He reaches for her hand. "He's not just my carer, he's my husband," she says. "MS is part of me, but it doesn't define who I am. We have enough other things we care about: his career, what's going on in Gaza, the Obama election..."

And the campaign to make assisted suicide legal. Debbie's dream scenario involves the DPP doing as she wants, allowing her not to have to think about the clinic for a while. Then she will fight for a change in the law, so that those who are suffering can enlist the help of the medical profession. "That would buy me even more time. Then there is always the hope that stem cell research will find a way to help MS sufferers function again."

She describes what is happening to her body by comparing the nerves to electrical wiring. The plastic covering around each wire, which stops the current leaking out, is the equivalent to the fatty sheath around the nerve called myelin. MS happens when the myelin deteriorates. "My brain is functioning, and my feet are functioning, but the messaging system between them is not."

She is in pain all the time, with poor circulation, a bad back, headaches, bed sores and muscle cramps. "Sleeping is very hard sometimes because the pain is too much." She is no longer able to exert enough pressure to use a knife and fork, so feeds herself with a bowl and spoon. Once or twice a week, she falls in the shower, presses her panic button and waits for "complete strangers" to come and help. Sometimes they have to clean her up, if Omar is away and her catheter is not working. "People say that is undignified," she says. "I don't find it so. It is undignified to find that I have no control over my life or death."

She is not afraid of dying, she says. "Once you're dead, you're worm food. It's the process of getting to that point which really frightens me. I don't want to be in unbearable pain." Nor does she trust herself to commit suicide, for fear of botching it. "In Switzerland they say to you, before the medication: 'If you take this, it will kill you. Are you sure it is what you want to do?' There are no ifs or buts. That is the option I find most appealing."

Earlier this month Gordon Brown said he was "totally against" a change in the law, saying: "It is not really for us to create any legislation that would put pressure on people to feel that they have to offer themselves [for death] because they are causing trouble to a relative or anyone else." She calls that "facile. I could give him evidence from America or other countries that it does not happen."

She has written to the Prime Minister asking for a meeting, but has not received a reply. If he ever does agree to see her, he'll get an earful. "The Suicide Act was established in 1961," she says. "I hadn't been born. Homosexuality was illegal. Abortion was illegal. We hadn't landed on the Moon. We hadn't had the Vietnam War. There had been no heart transplants. Martin Luther King hadn't even shared his dream. It's a different world. Surely we need to revisit this law now?"

Omar listens patiently to this passionate speech and smiles. Upstairs, in his music room, he plays a beautiful song he has written for her and will soon record with Courtney Pine on an album of his own compositions. Is he frightened of what life will be like after she has gone? "Very much so."

Will he let her go off to the clinic alone? "That is a fight we will have to have." If she insists, for his sake, then yes. "It is not my decision." But he also knows how hard it will be, because as anyone who meets Debbie Purdy can see, there is a hell of a lot of life in her yet. "Do you think she is ready to go to Switzerland now? No. Not in a million years."