Sir Dirk reveals `living will' wishes after stroke.
The actor and novelist says he can "no longer do anything for myself" and needs 24-hour nursing after being struck down two years ago.
Sir Dirk has drawn up a "living will" which states he does not want life- prolonging treatment if his condition worsens and becomes "incurable".
The 77-year-old film star says he is not ready to give up hope yet, but he adds: "If I am going to be paralysed and in a wheelchair for the rest of my life, I'd much rather be given something and put to sleep."
Sir Dirk went into hospital in 1996 for minor surgery to unblock an artery in his leg but suffered a "colossal" stroke after the operation.
"For at least a week I was sedated," he told The Daily Telegraph. "Only when I emerged from the hazy distance could I talk."
He adds: "I had realised by this stage that my left leg, arm and hand were incapable of movement. It didn't matter so much in bed, but it did everywhere else.
"I asked nervously if it meant that I would never be able to walk again and that I would be wheelchair-bound for the rest of my days. They all looked uneasily at each other or at their fingernails.
"I was told it depended on how determined I was, that it would take time, that you can't rush health."
Sir Dirk, who moved back to Britain from France in the late 1980s, was eventually allowed home where he has been receiving round-the-clock care in a specially-modified flat.
He says: "Writing is now impossible: I can only work through dictation. And here I still am, unable to do anything for myself."