BRAVE country legend Alan Jackson is desperately pushing ahead with one final tour as a rare neurological disease threatens to imprison him in a wheelchair forever!

The 63-year-old "The Older I Get" singer revealed he suffers from incurable Charcot-Marie-Tooth disease, a degenerative disorder that assaults the nervous system and will soon end his days as a performer.

"It breaks his heart that he knows his touring days are ending, and he wants to say farewell to his fans from the stage," says an insider. "In the past couple of years, his symptoms have gotten really pronounced.