The foreign secretary has confirmed Shaker Aamer is being released after almost 14 years of being held without trial at the US military prison in Cuba.
Virginia Moffatt, from Ekklesia, told Premier's News Hour: "He hasn't seen his children grow up, and he said very potently recently that he hopes to be released for his daughters 18th birthday, and thank God he has been.
"You can never take that time back."
Asked about compensation Virginia Moffatt said that there is no money that can equate to this: "His lawyers were very worried a few years ago about the fact he has lost so much weight from constant hunger strikes, his mental well-being because of his time in solitary, the fact he's been tortured - all of those things are very, very damaging as well as a loss of your freedom.
"I don't think there's any amount of money that can re-compensate that.
"But I do think compensation is owed to him, and a huge apology from all who were involved in incarcerating him."
In 2001 Mr Aamer was seized in Afghanistan, where he claims he was working for a charity, by bounty hunters who handed him over to US forces. A year later he was transferred to Guantanamo Bay accused of aiding Al-Qaeda.
The 46-year-old was born in Saudi Arabia, but his wife and four children are British citizens.
Shadow chancellor John McDonnell, chair of the Shaker Aamer All-Party Parliamentary Group, said: "I am delighted to hear this news and I'm breathing a heavy sigh of relief along with other campaigners who are happy that Shaker can now finally return to his family.
"Shaker was simply a man in the wrong place at the wrong time, a charity worker building wells in Afghanistan who was kidnapped, ransomed and falsely imprisoned.
"He has been cleared twice for release, never charged and no serious evidence has been presented against him.
"I am grateful to the Prime Minister for his intervention in the past year, and the cross-party support we have received for his release.
"I hope that he now gets the full support he needs so that he'll be able to settle back into society, and get on with the rest of his life."
Mr Aamer said that after more than a decade as being referred to as 239 - his prisoner number - he was not sure if he would know how to respond to his own name.
Virginia Moffatt added that: "I'm horrified, anyone that's been incarcerated like that and has been made to feel like a non-human - if you're referred to by your number you're not being given human status - so that's horrific... that he couldn't even have ownership of his own name."
Listen to Premier's Hannah Tooley speak to Virginia Moffatt here:
