SO, WHO can you trust these days? It's a good question. Politicians? We gave up trusting them long ago, and a glance at the Campbell diaries shows why. The Police? A sixteen month investigation into cash for honours, involving multiple arrests (and the prime minister's collar being felt three times) produces no charges. As Private Eye's Ian Hyslop once put it: "if that's justice, I'm a banana".

We used to place our trust in the media, but the pillar of public service broadcasting, the BBC, is now in the dock for fixing phone-ins, staging dodgy quizzes, misrepresenting statistics. A BBC Scotland producer has been suspended for creating a fictional winner of a contest during the Children in Need appeal. The Queen herself has been misrepresented. And as we report today, even Newsnight has had to apologise for playing fast and loose with the truth; claiming during a pre-election debate that a survey of 50 top businesses had shown them all opposed to independence, when only seven firms had actually responded.

People have been rushing to defend the corporation in the wake of fiddle-gate, and as someone who worked in the BBC for many years, I willingly join the rush - though with reservations. It is still the honest broker in the increasingly crooked world of modern media. The fact that the BBC bosses have apologised so profusely, and have come clean about cases of abuse the corporation has itself unearthed, shows that at least they can be held to account. (Though I find it astonishing that no one has had to resign over this systemic breach of trust with the viewer. ) As an institution, the BBC remains a bulwark of our battered civil society, and a key element in our democracy. America has nothing like it, which is why their political culture has been debased. The thought of the BBC being privatised - as some have urged in the past week - is unthinkable. The commercial broadcasters are infinitely worse on trust, but because they are not funded by the licence fee, they are somehow allowed to behave less responsibly.

The regulator, Ofcom, was equally scathing about ITV and Michael Grade, the chairman of ITV, has admitted that there has been a collapse of standards throughout his organisation. Industry sources tell me that a recent internal ITV investigation discovered deception in almost every programme that involved viewer interaction. Why have these not been revealed to the viewer? Is that not a breach of their licence?

The commercial stations also make much of their cash now from those iniquitous quiz channels on digital, which defraud their audiences on a daily basis. A recent commons inquiry into premium rate channels, revealed that questions were shamelessly rigged. One question asked phone-in contestants to guess what things a woman might keep in her handbag. One of the correct answers was: rawlplugs. They also kept hundreds of callers hanging on on premium rate lines, in the hope of being allowed to put their question. The chances of actually being selected was around 800-1. So, one caller gets to answer rigged questions, while 800 sit waiting on quid a minute premium lines. Talk about a licence to print money.

These dodgy practices are rife within the industry, and since the BBC has been casualised, outsourced, multi-skilled and marketised, it is hardly surprising that they are being discovered in the BBC. The corporation is a very different organisation to the one I joined over 20 years ago. Insufferably bureaucratic at times and institutionally conservative, the BBC nevertheless was a secure and confident place in those days, a cultural standard bearer which new right from wrong and observed the highest standards of accuracy.

So dedicated was the Beeb to getting things right that it tended to avoid breaking stories because it couldn't risk getting anything wrong. Most Westminster stories in the press are based on unattributable, off the record briefings - the practice is institutionalised in the Lobby system. This is an open invitation to disreputable journalists to make quotes up, and to my certain knowledge after working in the Westminster Lobby for nearly 10 years, quotes were very often "adapted" to fit, or invented altogether.

On the occasions that the BBC does try to run pieces based on unattributable briefings, it tends to come unstuck. I had just moved to the BBC's political unit in Westminster in 1989, when the then chief political correspondent, John Sergeant, ran a story that Mi5 was investigating Labour politicians' links with Soviet Russian officials. The story had come from an off the record lunch with William Waldegrave, the Tory minister. But as soon as it was read on the Nine O'Clock news, all hell broke loose, and the foreign office denied it, leaving Sergeant with a credibility crisis. The story would have run on any broadsheet newspaper without any comeback - and indeed it subsequently re-emerged in print.

Of course, different standards are required in political journalism than in pop phone ins on BBC radio 6. But as Michael Grade said, the cardinal rule for all broadcasters should be "you do not lie to audiences at any time, in any show - whether it's news or whether it's a quiz.' This tradition of authenticity used to be very deeply ingrained in the BBC because it was enforced by editors and producers who regarded themselves as having an almost sacred duty not to deceive. This was often a Quixotic task, since of course, television involves artifice at almost every level. Whenever you see an taped interviewer nodding, smiling or reacting with a knowing or quizzical eyebrow, you are generally watching what are called "noddies" - reaction shots filmed after the interview takes place.

But the people who used to make BBC programmes were real sticklers for accuracy and sometimes went to extraordinary lengths in their mission to be true. I once made a television documentary with a time-served BBC producer about Scottish heart patients who were having to go south for operations because there were no adequate coronary facilities in Scotland. Many of them died on the way. We arranged to film one middle aged man who was taking the long trip as he said good-bye - possibly for the last time - to his wife and family.

Now, I assumed that we would take some shots of the family at the bedside, and then leave them in peace to make their own farewells. But the producer was having none of it. If we were going to say that this was the man saying good-bye, then it had to be the real good-bye - otherwise we would have to say that it was a 'reconstruction'. I was appalled and stomped off, assuming that the man would surely not allow his privacy to be invaded by cameras and lights at such a delicate and emotional moment. But to my surprise, he and his family agreed.

Now, I could see that this was an ethical dilemma but it seemed to me to represent an obsession with authenticity, a fetish even. The mere presence of a film crew at the bedside automatically made the exercise artificial. It is almost impossible to make real "reality television" because as soon as there is a camera, lights and microphones, present it ceases to be real. But I couldn't help but respect the producer for her dedication to what she believed to be ethical broadcasting. There would be no place for her in the modern industry.

The industry is now staffed by very young people, rarely over 35, who move from programme to programme on temporary contracts, desperately trying to get noticed. It is a professional environment ripe for abuses - nepotism, exploitation, deception, sexual harassment, ageism - and all human life is there.

Network television is a very nasty place to work nowadays, in the hothouse atmosphere of commercial competition where the only morality is the bottom line. And with digital coming, it can only get worse. Which is why we need the BBC more than ever, even if Auntie has shown her knickers. Let's hope she keeps them up in future.