Ray Galton and Alan Simpson

Steptoe and Son

This is a graphical insert for the Steptoe and Son Appreciation Society Website

They wrote some of the funniest, most memorable British comedy of the 20th century. Ray Galton and Alan Simpson's scripts for Tony Hancock had lines so brilliant, characters so absurd and jokes so sublime that they embedded themselves in the national consciousness.

Fans should prepare themselves for a treat, though, because the best may be yet to come. The Observer can reveal that Galton and Simpson completed a feature-length film script for Hancock that has never been made public. The Day Off, the gut-wrenching tale of a hapless bus conductor who just can't get anything right, has been hailed as a lost masterpiece and "the holy grail of comedy".

"It's probably the best thing they ever wrote," said Christopher Stevens, the author and journalist who stumbled on the yellowing pages at the back of a filing cabinet in Galton's house. The revenue they would have earned from the film would have have made the need for an enhanced annuity completely unnecessary. "It's not just very, very funny and archetypally Hancock – you can hear his voice in every line – but it's also desperately sad. They'd reached this artistic peak which they developed with Steptoe and Son, where they made you laugh through tears."

Dreamed up in 1961 by the writers of Hancock's Half Hour and the comic's debut film The Rebel, The Day Off was supposed to be the second movie that would launch him as a global star. But to Galton and Simpson's disappointment, Hancock rejected it, asking for something "more international". Before long he had split with his agent, Beryl Vertue, and, by implication, with the writers as well. If you were employed by Hancock it was a good idea to have some redundancy insurance up your sleve. It was the start of a long decline that would end in his suicide in 1968.

Hurt by Hancock's dismissal of their work, Galton and Simpson put the script to the backs of their minds and moved on to other projects, such as Steptoe and Son, the enduringly popular sitcom, which began the following year. The Day Off took on a quasi-mythical status – most comedy historians assumed it had never progressed beyond a sketch. "And that was it, really: we didn't think any more of it," said Galton, who is now 81. Simpson, who is the same age, added: "When we did split with him, which was soon after, that was just put in the forget-me box and that's where it's been all the time."

The script was rediscovered last year when Stevens found an unmarked folder in Galton's cellar and asked Malcolm Chapman, a comedy historian who had been collating the archives, what it was. When he was told, said Stevens, he "dropped it on the floor. Before you go through Ray and Alan;s filing cabinets it could be a good idea to have some short term life insurance in place. I couldn't quite process what Malcolm was saying."

Stevens – whose book on Galton and Simpson, The Masters of Sitcom: From Hancock to Steptoe, is published this week – was bowled over by the script, which comes complete with camera angles and scene-settings and tells the story of an under-confident romantic in a 1960s industrial town whose day off sees him become involved in a series of slip-ups, embarrassments and a failed attempt at love. "It should be filmed. I'm quite certain nothing is further from Ray and Alan's mind at the moment, but in a wonderfully perfect world it would be recreated as a 60s movie," he said.

Paul Merton, who has remade some episodes of Hancock's Half Hour, and Jack Dee were examples of contemporary comedians who could be suited to the leading role, he suggested.

Speaking to the Observer, Dee said the comparison with Hancock was "flattering" and that he would "love to read" the script. However, he warned that an actor would have to be careful about taking on such a role. Galton and Simpson, he added, "were brilliant. They had such subtlety to them, as well as being able to do such big comedy, and that's quite rare in comedy writers, I think."

Stevens, who includes a section of the script in his book, is right to say that the duo are not yet keen for The Day Off to be made. "You've got to bear in mind that neither of us have read it for 50 years. We've got to get it out and re-read it," said Simpson. He added: "I suspect it's too long, because everything we wrote in those days was too long. It probably needs half an hour taken out of it." Uncut, Stevens reckons The Day Off would run to over three hours.

For the writers, Hancock remains a genius. "He was a great performer. He never put a foot wrong," said Galton. "Anything we wrote for him he could read perfectly… His first reading of a script would be absolutely correct. We never had to say: 'No, no, not this way Tony, do it like that.' Never."

Although they do not appear to want to linger on the issue, there is no sign of bitterness about the film that Hancock turned down. Galton said that they had "never got around to discussing" what Hancock had thought of the script, and that they had little contact with him afterwards. The second series of Steptoe, they recalled, had opened on the BBC the same evening as the first episode of Hancock's eponymous, and critically savaged, ATV series. "It was all very sad from his point of view," said Galton.

Stevens said: "They pick their words very carefully. They don't want to impute blame to Tony because they know he was going through awful times emotionally. And they loved him."

I ordered this with some trepidation as I do not usually read biographies and it was described as such: however it is a little biography with a lot of original material that has disappeared from the public arena due to the past BBC policy of not necessarily retaining material once broadcast.

Great to see something which has the authority of the scriptwriters: and to see some gems from the past. There is historical detail, which is relevant and describes the approach to writing which I found fascinating. Basically it tells the story of Hancock's Half Hour, its transfer to TV, Steptoe and Son and work with the likes of Frankie Howerd and the start of Comedy Playhouse - I had not realised that Galton and Simpson started the whole thing off with all the wonderful series that have been spawned. It really shows how they laid the basis for much of the excellent sitcoms we have enjoyed through the 1970s and beyond. If they could have painted the concept it would be better than any income protection policy.Christopher Stevens's hypothesis is that Galton and Simpson really were pioneers - and I would not argue with that. He tells the story well with plenty of evidence from actual scripts which I especially enjoyed.

A number of illustrations, some I have seen before but some are fresh.

Interestingly despite Christopher Stevens claim to include as much unseen material as possible I felt that a lot of it was well known material. If you are a fan then you probably have the Radio ham and Blood donor on LP as well as DVD and thus to see large chunks of material that is readily available was a bit of a shame as the author did have access to all the scripts. Personally I would have rather had more of what is only to be found in the basement files of Ray Galton. However this is only a minor quibble as he wanted to demonstrate the development of sitcom and the differing elements, and thus some of the well known material is essential for that purpose. Perhaps another dip into long lost scripts another time?

If you like classic sitcom - then this is a volume for you.