Former IBF, IBO, WBA, WBO heavyweight champion Tyson Fury (25-0, 18 KOs) is now biting at his lips to get back in the ring.

He believes his two years of inactivity is similar to the political battle that prevented heavyweight legend Muhammad Ali from fighting several decades ago. Ali was on the shelf for nearly four years after refusing to enlist in the U.S. Military while the Vietnam war was raging on.

Fury's return to the ring has been delayed due to his ongoing battle with UK Anti-Doping (UKAD) - who claim the boxer tested positive for a banned substance in early 2015.

Fury, 29, has not fought since traveling to Germany to unseat Wladimir Klitschko in November 2015 for the heavyweight titles.

One by one, he lost all of his world titles - and then lost his license to box last year after admitting to his battles with depression and recreational drugs like cocaine.

Fury's UKAD hearing has been delayed over and over with no reason given. It is scheduled to take place this month.

"I am being kept out of the ring by political stuff -- they did the same to Muhammad Ali. Two years [I've been] out of the ring. They kept Ali out for three years and seven months. It didn't affect him. He went down as the greatest," Fury stated on social media.

Fury is back in training and receiving a lot of help from former world champion Ricky Hatton.

According to Hatton, the former heavyweight champion is losing a lot of weight, his quick foot work has returned, he is sparring hard and his reflexes are very fast.

"I'm working hard. I'm training hard, and everything is going good," Fury said. "The weight is coming down, the money is rolling in. I am happy with what I achieved in my career, but there's an old proverb; 'you can't keep a good man down.' And that is what I am, a good man, and you can't keep me down, no matter what anyone says.

"It would take some man to put Tyson Fury on his back."