A British man dying from kidney failure has been given one month to live, unless his wife loses the weight necessary to provide him with a healthy kidney.

Samantha Lamb, 36, is the perfect donor for her husband, Andy, 40, who is suffering from renal kidney failure, the U.K.'s Daily Mail reported. However, doctors will not perform the operation on her unless she loses 14 more pounds.

Through a strict diet and two hours of exercise per day, Lamb has already lost 35 of the necessary 49 pounds she must drop to have the surgery.

Without the donated kidney, Andy, who is living off dialysis, could die within a month. He is on an emergency donor waiting list, but his best chance of survival rests with his wife.

"This has been the biggest challenge of my life but it's the only challenge that's worth doing, Lamb told the newspaper. "What better prize than saving my husband?"

Click here to read more on this story from the Daily Mail.