It was the summer of 1983, and John Sullivan was on a caravan holiday in Hastings with his wife and two children. It had been a difficult few months for the writer, who had been earmarked as one of the brightest new talents at the BBC. A socialist, he had watched in despair as the Conservative Party delivered Labour its worst defeat since the 1930s. more importantly for him, his future as a scriptwriter hung in the balance. His agent had just informed him that his sitcom, Only Fools and Horses, was set for the axe after just two series.

The ratings failure of Only Fools and Horses came as a surprise to all of the people who had worked on it. Sullivan had earned his stripes in the 1970s with Citizen Smith, a sitcom centred around the hopes and dreams of Wolfie Smith and the Tooting Popular Front. Smith agitated for a political revolution — if only to stave off the realities of work, relationships and middle class suburbia. Derek Trotter had dreams too. He dreamed of one day becoming a millionaire. In the early 1980s, becoming a millionaire from selling one-legged turkeys on a Peckham market stall seemed about as likely as organising a political revolution from a bedroom in Tooting. Sullivan’s comedy lay in the contrast between the dreams and the realities of working class life.

People were told, in essence, to go out and do it for themselves

But while Citizen Smith drew in regular audiences of 22 million, Only Fools and Horses struggled to hit half as many. Few people, it seemed, wanted to watch a comedy about life at the hard edge of Thatcher’s Britain. Sullivan situated the Trotters in the ever-expanding black economy, as secure employment prospects vanished for millions of people. In the opening episode, Big Brother, Rodney Trotter is ridiculed for even thinking about getting a proper job. “At the ripe old age of twenty-three, you are a social leper,” Del tells him. “Society has placed you in the darkest corner of its deepest cellar to grow moss and be forgotten about.”

In the month that Only Fools hit the airwaves for the first time, the new Employment Minister Norman Tebbit took to the stage of the Conservative Party conference to tackle the issue of unemployment head-on. As riots spread across the country, the pressure was mounting for some form of economic intervention. Instead, people were told to get on their bikes and look for work, as his father had done in the 1930s. They were told, in essence, to go out and do it for themselves.

Only Fools was a sitcom about people trying and failing to do just that. Del Boy was arguably a Thatcherite before the term had even been invented, declaring, in the show’s opening scene, that he doesn’t take anything from the government in welfare — so he doesn’t give them anything back in tax. While the government never openly encouraged the black market, ministers increasingly relied on people like the Trotters to prop up the real British economy — the one not being measured in the official government statistics.

Those early Only Fools episodes served as a social commentary on the insecurities of working-class life in the early 1980s. There was little evidence that the public became enamoured of characters who were engaged, as the Daily Telegraph described it, in “seedy criminality”. One reviewer concluded that the writing was probably “too quirky, too seedy, too socially acute to attract enough morons to keep the ratings high enough”. When it came to comedy, viewers preferred the cosiness of Ronnie Corbett’s Sorry! (1o million) and Terry and June (11 million); the nostalgia of Hi-de-Hi (12 million), Last of the Summer Wine (16 million) and Open All Hours (13 million); as well as the slapstick of ITV’s Benny Hill Show (18 million).

Most of all, BBC executives pointed to the remarkable success of To The Manor Born, which pulled in record audience figures of 24 million. Like Only Fools, it was a sitcom about class and aspiration in the early Thatcher years. But this was about the tensions between old and new money as Audrey Forbes-Hamilton, played by Penelope Keith, fell upon hard times. In a changing of the guard, she sells the Grantleigh Estate to the owner of a chain of supermarkets. Only Fools, in contrast, was about the tensions between groups of people who often had no money at all.

Sullivan’s greatest fear — as a working class writer — was that he would not be able to write again. Then just as the BBC was ready to pull the plug on the show, something strange happened. In June 1983, just weeks after Thatcher’s landslide election victory, the technicians at the BBC called a strike. Their union was in dispute about the hotel allowance for staff who were working away from home. The union wanted a flat fee of £34.84 regardless of the cost of a hotel. The BBC disagreed and a standoff ensued. Royal Ascot and the Cricket World Cup were pulled from the screens. In a panic to fill the schedules, somebody plucked out an episode of Only Fools from the archives.

Repeats saved Only Fools from comedy oblivion

The first John Sullivan knew of the repeat was when he picked up a copy of the Daily Mirror while on holiday in Hastings. The show had been the fifth most-watched television show of the week. When the BBC chose to repeat another episode, it hit number two in the ratings, beaten only by the nine o’clock news. By the time Sullivan returned to London, he had been offered two more cracks at the series. It was repeats that saved Only Fools from comedy oblivion, and it has been repeated on our television screens ever since.

The strike set off a chain of events that would change the course of television history. Only Fools went on to establish itself as the most popular television programme of all time. With each series and Christmas special, people grew to love the characters as if they were part of their own family. By the end of its original run in 1996, it achieved Morecambe and Wise levels of attention (almost half the population) in an era where cable television was competing for eyeballs. Del Boy was thought to be so influential by the end of its run, that when he was pictured reading a copy of the Daily Mirror, the Major Government launched a complaint to the BBC. They believed that the show would encourage people to vote for New Labour.

The appeal of Only Fools came, in part, from Sullivan’s unique portrayal of working class life at a time when those communities appeared to be under threat. The 1980s were supposed to be the age of the individual, the era where there was “no such thing as society”. Only Fools centred around a tight community — the tower block, the pub, the café — which, at times, holds Del Boy back from achieving his ambitions. Sullivan argued that “Del and Rodney do show that people are greedy”, but that “their humanity also comes through”. “Perhaps,” he concluded, “they just aren’t very good at being greedy.”

Sullivan’s foresight as a writer was in understanding how the sitcom medium was changing and moving towards the realms of drama. In the feature-length episode To Hull and Back, the show offered a glimpse into what the modern sitcom would look like when it broadcast without a laughter track. As it became more popular, it moved from the standard 30 minutes “situation” to 50 minute comedy-drama to eventual feature-length television movies.

In its desire to project the realities of life, no subject appeared off-limits. In 1984, when the cast was rocked by the death of Leonard Pearce — who played Grandad — a decision was made to write the funeral into the show. It was a radical departure in the sitcom world where characters often just disappeared or were replaced by other actors without explanation. Sullivan chose not only to write a funeral episode, but turn Strained Relations into a conflict about how two brothers dealt with grief differently. It set the standard for a sitcom that often blurred the boundaries between comedy and tragedy. In later years it tackled deaths, divorce, redundancy, failed adoptions, infertility and miscarriages, on the way to the brothers finally becoming millionaires.

Since it departed our screens in record numbers (over 24 million watched Time On Our Hands) the show has been revived, subject to spin-offs (Green Green Grass), prequels (Rock and Chips) and enjoyed a run as a West End musical stage show. In 2004, when the BBC undertook its quest to discover Britain’s Best Sitcom, there was no doubt that Only Fools would come out on top as the “people’s favourite”. In the social media age, clips now lend themselves to memes and viral shares, with the official Facebook page reaching 1.2 million fans each day. On its 40th anniversary, the BBC hopes to cash in with a dedicated online merchandise shop, while UK GOLD has set up a pop-up Nags Head pub in Farringdon with beer served for 1981 prices.

References to the IRA and “paki shops” have been cut from repeat viewings

The continued influence of a show that first entered our world forty years ago is not without its critics. To some, it is a sign that British comedy is not as influential as it once was, and that nostalgia has gripped our pop culture. It would, for example, have been absurd in 1981 for people to be still emotionally invested in a popular programme from 1941 (such as It’s That Man Again). To others, its continual presence at the top of list shows that declare scenes to be the “funniest moment of all time” have long removed any of its humour (see the brilliant Stewart Lee satire on the town that recreates “Del falls over and Trigger pulls a face” each year).

More seriously, there are growing calls for the show to be re-examined in the light of recent social change. Last year, a journalist writing for MyLondon claimed to have given up watching the show after just 30 seconds, believing it to have set a “sinister tone for yet another racist and sexist show”. Indeed, Del describes women as “tarts”, “dogs” and “birds” and is uncomfortable around homosexuality. His references to the IRA and “paki shops” have been cut from repeat viewings. Recently, comedians such as Paul Whitehouse (who stars in the West End musical version of the show) were forced to defend it as “not racist” and asked it to be judged as a product of its time.

Before a potential backlash occurs, it is worth remembering that Sullivan always intended to write the characters with faults and contradictions. He didn’t romanticise their behaviour and was eager to elevate prejudices for comedic effect. For example, in a now controversial scene in Go West Young Man — where Del Boy refers to a waiter in a gay bar as a “bandit” — the scene is actually set up to show the absurdity of Del’s masculinity, when he has to explain the ingredients of his exotic cocktail. In another episode, Del is shot down by Raquel when he claims that “women are dodgy” during a discussion of the AIDS crisis. Sullivan’s talent was to have the viewers rooting both for and against the characters, often in the space of the same scene.

Those nuances and contradictions within the characters give the show its social realism and no doubt underpin its long-term success. While Only Fools is essentially a show about working-class aspiration in the Thatcher Years, you wouldn’t be able to tell Sullivan’s socialist politics from the writing. Take, for example, the scene from the episode Yuppy Love when we see the brothers split over one of the most contentious political issues of the age: the Right to Buy. Del wants to purchase the flat and sell it some “some chinless wonder” for a “vastly inordinate sum”, in order to buy a nicer house for the family in the suburbs. Rodney, meanwhile, believes that the sale of council houses is “immoral” and that it will force the working classes out of London altogether. Del thinks that the discount on the Peckham flat is only fair when you consider how his rent for 27 years had probably bought the flat many times over. It was a scene that summed up the social complexities behind the debate in a way that no documentary or political speech ever really could.

For that reason, Only Fools should be celebrated as it reaches its 40th anniversary this week. Over time, we may move on from the comedy of the show, but it will always serve some historical purpose as a monument to an important moment in 20th century Britain. Perhaps its enduring popularity says more about the changing nature of sitcoms as an art form, than it does about the state of modern comedies. We seem to have little trouble romanticising and reviving the plays of Shakespeare, Noel Coward and Harold Pinter for each new generation. So why shouldn’t the writing of John Sullivan and acting of David Jason and Nicholas Lyndhurst be immortalised within our culture? It’s nothing less than they deserve.