Much has been said about how different government was when we first wrote Yes Minister - since the late 1970s, people say, the civil service has been politicised and the introduction of special advisers (otherwise known as spads) has changed everything.
So when we considered writing the stage play Yes, Prime Minister, to coincide with the 30th anniversary of the series, our first questions were: are things different now and, if so, would our task be more difficult? It turns out that most things haven't changed much at all.
There have always been special advisers. We had one for Jim Hacker in the first series; we got rid of him because he seemed too identifiable with Labour, which was in office when we wrote the first seven episodes. We knew two of them: Marcia Williams, Harold Wilson's political secretary and confidante, and Bernard Donoughue, head of the No 10 Policy Unit under Wilson and Callaghan. Then came Thatcher and her close adviser Bernard Ingham. Yet, under Blair, Alastair Campbell created such a cult of personality that everyone thought his role was new. It wasn't.
Is the civil service more politicised now? We don't think so. It is in its interest to look as though it supports the government on everything, both practical and ideological. That's what they are paid for. It is not in their interest to broadcast their own agenda. That's our job.
So, has anything changed? The answer is yes. Society has. "Shame!" MPs traditionally shout when they disapprove of something. What does that mean? Does it mean "What a pity"? Or that the statement was a shame, or worthy of shame? Or is it an instruction: "You should feel shame"? If an order, it's likely to fall on deaf ears. Since we started to write Yes Minister, shame went out of style.
Politicians, like other celebrities, reflect our society. Remember John Profumo? He had sex with a prostitute, lied to the House, and spent the next 40 years in penance. Twenty years later Cecil Parkinson, a married man, had an affair with his secretary; she went to the newspapers with the story - no shame there, apparently - and nine years later Parkinson accepted a peerage and became chairman of the "family values" party. Embarrassment, yes. Shame? Not so much. We are not moralists about sexual conduct but all satirical writing involves a moral standard, frequently self-imposed, which is not being met. Our concerns are hypocrisy and dishonesty, because those are usually the funniest. But in looking for subject matter for the play, we looked for things that still shock people. We couldn't find very many.
MPs fiddling their expenses seemed worth a mention but not much more: after all, that system was deliberately designed by the Callaghan government as a way to get around the pay freeze. MPs were supposed to inflate their expenses. They were expected to do it discreetly, however, and weren't expected to commit actual fraud such as claiming for paid-off mortgages, or duck houses, or moat-clearing. But they virtually all did it and no one felt guilty. Shame had been replaced by embarrassment - horror at what you have done replaced by horror at people finding out what you have done.
In the TV series we typically had a plot and a subplot in each episode, so that Jim and Humphrey would have leverage over each other. A play has much greater scope - and, after all, sometimes five or six major crises may come to a head simultaneously. We decided to set the play at Chequers. It would be about one Friday night on which a European conference to save Greece, Ireland and Portugal is collapsing, Jim's coalition is falling apart, the BBC is out to get him, an illegal immigrant is discovered working at Chequers, and Sir Humphrey tries to force Britain to join the euro and has leaked insider information to a bank to secure his comfortable retirement. We needed one further ingredient, a hideous dilemma that must be kept secret. A truly shocking sex scandal might be the answer.
But what could that be? Sex scandals are just not shocking any more: the head of the IMF is accused of trying to rape a hotel chambermaid, John Major has an affair, John Prescott has a "two-year fling" with his diary secretary, after which he issues this statement: "I have discussed this fully with my wife, Pauline, who is devastated by the news. I would be grateful if Pauline and I can now get on with our lives together." Is it possible to parody this? Probably not.
This is how the Mirror reported the fling: "Mr Prescott was spotted springing out in front of her while pulling a funny face to make her laugh . . . The level of flirting between the pair began to rise . . . The horseplay and suggestive remarks were transformed into a full-blown affair at the office Christmas party in 2002. As soon as Mr Prescott arrived he jokingly lifted her skirt to see if she was wearing stockings."
Topping it all, Prescott's old boss Tony Blair writes in his memoirs about having fantastic sex with Cherie when, following God's instructions, he goes to war in Iraq. What made him think we would want to visualise this?
But there is one sort of scandal that still shocks the public: enter Mr Berlusconi and his bunga bunga parties with underage hookers, which hit the papers just in time to validate what we had written. Our play is as shocking as the headlines. No more, no less. As Will Rogers said, "There's no trick to being a humourist when you have the whole government working for you."
Jonathan Lynn and Anthony Jay's "Yes, Prime Minister" is reopening at the Apollo Theatre, Shaftesbury Avenue, London W1, on 6 July