Shirley has always claimed he is innocent

Over the past 13 years, Shirley has held rooftop protests, sent hundreds of letters and been on a seven-week hunger strike in an effort to clear his name.

Pat Shirley, Michael's mother, told BBC Midlands Today: "Even last week he was threatening to go on another hunger strike.

"He's just devastated."

She blamed the Crown Prosecution Service (CPS) for its failure to act swiftly since the Criminal Cases Review Commission referred the case to the Court of Appeal.

"Every time we try to find out what's going on or what the deal is, they're just shutting the door on us.

"We don't know when we're going to be getting a date or anything."

Pat Shirley blames the CPS for the delays

The CPS says it is waiting for Shirley's defence team to discuss forensic evidence.

The team denies it is responsible for the delays.

Michael Shirley was on shore leave in Portsmouth at the time of the killing of Linda Cook.

The 24-year-old barmaid was attacked as she walked home from a friend's house in Portsmouth to her home in Southsea, roughly a mile away.

The murderer stamped so hard on her body that he left an imprint of a logo on his shoe on her body.