The late Dr Brian Jones was an intelligence analyst who worked for the Defence Intelligence Staff from 1987 to 2003 as an expert on the counter-proliferation of weapons of mass destruction (WMD). His was one of the voices on the intelligence staff that raised concerns about the dossier released by Tony Blair's government relating to Saddam Hussein's WMD, which was used as a justification for the invasion of Iraq in 2003.

On the tenth anniversary of the invasion, BBC Radio 4 are airing a drama written by David Morley that attempts to re-create Jones's struggles to stop exaggeration and inaccuracies creeping into the dossier. Richard E Grant stars as Jones and Spooks star Peter Firth re-creates his role as the head of a spy network, playing Richard Dearlove, the head of MI6.

Morley describes the genesis of the drama as quite a simple thought process. He noticed that March 2013 would mark ten years since British forces invaded Iraq and wondered if there was any way he could create a drama around that, in a way that hadn't been done before.

“We [Morley and producer Richard Clemlow] felt the politics of the lead-up to the war had been done in quite some detail and the whole business of the legality of going to war had been done in a few dramas, TV not radio. So we went to say to the commissioner Jeremy Howe, look we want to do something about Whitehall, something about what was going on behind the scenes in Whitehall in the run-up to the war.”

Howe gave his consent and told them to get cracking. That's when the hard work began. A reseracher was given the mammoth task of trawling through the Hutton Inquiry, the Chilcot Inquiry, the Butler Report and various other inquiries about the war. By the end Morley and Clemlow had amassed a huge amount of evidence as to what was going on.

Morley sifted through that mountain of text to find a way of navigating through the complex issues thrown up by the politics of making a case for war.

“There's been so much written about it, I think it's hard to see the woods for the trees.”

But Jones's story offered a simple way of producing a narrative from what is essentially a dry set of legal documents, and Morley encapsulates it in a similarly easy-to-understand manner.

“Jones tried to stop what became known as the "sexing up" of the dossier [on the instructions of] Alastair Campbell and various other people. Unfortunately he was stopped from doing that by his bosses, who told him to shut up. That, essentially, is the story of the drama.”

Though producing a drama from evidence submitted to multiple inquiries may have its problems, it also has its advantages, especially with a radio drama. Morley was able to take many emails and memos and dramatise the words exactly as they were written. Most of these were taken from the inquiries' evidence but Morley did also use leaked sources and others released to journalists under freedom of information requests. He also talked to interested parties such as people at BBC News and the Today programme, and Gordon Corera, the BBC's security correspondent, and Andrew Rawnsley, who had covered the subject in his book on the Blair years.

But the main source was Brian Jones himself. Morley spoke to him several times, with the last time being three months before his death in 2012 aged 67, when Jones seemed to have an intimation of what was going to happen. Morley remembers that conversation well.

“The last time I spoke to him, he said he wasn't feeling very well, because he was cancelling a meeting with me. So I asked what was wrong, and he said his doctor said he had shingles, but he felt it was something more serious, and three months later he was dead.”

He has fond memories of Jones, not just because of the help he afforded him in writing his drama.

“He was a very nice guy who felt it was his duty to inform his bosses and he hoped inform Alastair Campbell and Tony Blair that what they were putting in their dossier was an exaggeration and inaccurate, but he was not successful.”

The last time that Jones spoke to Morley he hinted at an extraordinary bit of information that the writer had not heard before. Jones had previously told him, and had written about separately, an episode in which spies from a foreign country were invited to Downing Street to take part in a meeting where they were shown a lot of the background information that formed the basis of the dossier. He'd never revealed the nationality of the spies, however much Morley asked, as he said that was covered by the Official Secrets Act. But during that final conversation he dropped a clue.

“Just before we stopped the conversation, he said, 'But they had been our enemies until quite recently.'”

From that Morley deduced that they must have been Russians, but the BBC was not going to be convinced by a verbal admission from one source. Morley and Clemlow had to build a case to take to the Beeb that it couldn't possibly have been the French or anyone else, for various other reasons. They won their case and the drama does feature a scene in which the Russian secret service are invited into Downing Street. A scene which Morley believes highlights an unprecedented moment in East-West relations.

“It's a bit odd to do that. They completely rubbished all the information that had been put in front of them and told them that there wasn't enough proof to base the 45-minute claim that Saddam could launch WMDs.”

The caution of the BBC in including that scene also applied to the drama as a whole, meaning that the majority of the script had to built purely from the evidence provided to the inquiries. It’s something that Morley admits could have a negative effect on the play, but he hopes that the subject matter in itself is enough to grab the interest.

“The BBC was obviously very, very careful that we didn't say anything that we couldn't back up. So as the writer there hasn’t been much leeway to step away from the facts and make a better drama. But it's been very exciting and interesting to write at the same time because of those kind of constraints. I think it's something you can listen to and think, bloody hell, did this actually happen. People did this, you know.”

Click below to listen to a clip.

Although he spoke to many people off the record, there was one source who Morley wanted to talk to but was unable to contact, a colleague of Jones who is referred to quite a lot in the book Jones wrote about his experiences.

“But his colleague has never been identified, so we have a character in the drama who we've called a different name, and I don't know who he is. He's never been revealed to the public. It's sort of a state secret who he is.”

Although Jones was concerned about the corrosive effects of inaccuracies creeping into the dossier, which certainly proved prescient, he never came out and said publicly that the invasion of Iraq should not have happened. Though Morley feels that may have been his true feelings on the matter:

“Most of his comments are reserved for the process of analysing the intelligence. I might be wrong about this, I'm sure he didn't think we should have gone to war, but I don't think he thought it was his place to comment on things like that. I think he felt he was only qualified to comment on the things that he knew about. In a way I think he was a creature from a different era. Certainly from the Blair era.”