- Alan Henning is being held captive by ISIS militants, who have threatened his life
- Henning's wife speaks out because ISIS captors won't engage in "dialogue," she says
- She notes Muslims have called for Henning's release; Sharia courts found him to be no threat
- "He went to Syria to help his Muslim friends deliver much needed aid," she said
Saying she'd just heard her husband "pleading for his life," the wife of Alan Henning delivered her own plea to ISIS on Tuesday, as well as a slap at the extremist group for threatening to kill the British aid worker who'd only gone to Syria to "help his Muslim friends."
In a message released by the British foreign office, Barbara Henning said that she had received an audio file with her husband's voice, but hasn't been able to contact those holding him.
"Islamic State continue to ignore our pleas to open dialogue," she said.
So -- without the chance to talk to his captors confidentially -- Barbara Henning instead made made another public pitch for her husband's life.
Barbara Henning noted the widespread sentiment voiced by Muslim leaders around the world calling for Alan's release. They include Shaykh Haitham Al Haddad, a judge on the Shariah Council in London, who has said that "whatever your grievance with American or British foreign policy, executing this man is not the answer."
"I have seen Muslims across the globe question Islamic State over Alan's fate," Barbara Henning said. "The voices of the people have spoken out loud and clear."
Similar to what she'd said in a message Saturday, Barbara Henning said that Alan had gone to the region -- not to join one side or the other, or to spy for a certain group -- but to do what he could to improve the lives of people in the region.
A taxi driver from near Manchester, England, Alan Henning was part of a team of volunteers that traveled to Syria in December to deliver food and water to people affected by the Middle Eastern country's devastating civil war. He was abducted the day after Christmas by masked gunmen, according to other people in the aid convoy.
"He was working with Muslims to help the most vulnerable within Syria. Nothing has changed," Barbara Henning said. "He went to Syria to help his Muslim friends deliver much needed aid."
Barbara Henning said she'd been told that a Sharia -- or Islamic law -- court had found Alan Henning "innocent of being a spy and declared (him) to be no threat." Why, then, would ISIS not "abide by the decisions of their own justice system?" she asked.
"We are at a loss why those leading Islamic State cannot open their hearts and minds to the facts surrounding Alan's imprisonment and why they continue to threaten his life," she said. "Please release Alan."
Yet ISIS hasn't shown any mercy yet to its captives, at least the ones it has trotted out before cameras.
This summer, the group beheaded American journalists James Foley and Steven Sotloff -- gruesomely showing their killings in videos posted online. ISIS then claimed its first British victim, aid worker David Haines, according to video that appeared online on September 13.
Henning appeared kneeling in that last video, with an ISIS militant standing menacingly by his side.
The families of Foley, Sotloff and Haines all issued public pleas for their loved ones' lives, but to no avail.
Barbara Henning on Tuesday voiced her frustration that her husband's captors won't even allow her to make a case to them directly. She noted that she and her representatives have tried reaching "out to those holding Alan," but they haven't gotten a response.