Writer and director Armando Iannucci has launched a passionate defence of the BBC and said British television needs support amid political attacks.
He warned that tampering with the BBC would be "madness", and that politicians - with no expertise in the area - have got the British television industry "completely wrong".
In a speech, the satirist warned that politicians could become "masters" of the industry, adding: "It will be a distracting interference and ultimately harmful to British television."
He was delivering the James MacTaggart Memorial Lecture, the keynote address at the 40th Guardian Edinburgh International Television Festival.
Just a few hours earlier, Culture Secretary John Whittingdale rubbished the idea that the BBC is to be "dismantled".
"I've never suggested dismantling the BBC," Mr Whittingdale told the festival crowd.
He also said that suggestions that there was an ideological Tory drive to destroy the corporation were "just extraordinary".
Mr Whittingdale has sparked concern among some supporters of the corporation after saying that a review of the BBC's royal charter would look at whether the broadcaster should continue to be "all things to all people" or have a more "precisely targeted" mission.
Oscar and Emmy-nominated Iannucci, who directed the cult hit I'm Alan Partridge and political comedies The Thick Of It and Veep, said: "Faced with a global audience now, British television needs its champion supporters, it needs its cheerleaders.
"Who will they be? The Government? Not while they consistently talk of reining in our greatest network.
"The broadcasters? Not while most of their energies are dissipated fighting off political attacks on their impartiality or finances.
"Now, of course, our friends in Whitehall would argue that, as the BBC's charter comes up for renewal, it's important to see how the Corporation can operate even more effectively.
"I'd argue back that starting a debate on how the BBC should be funded just days after lopping 20% off its budget without discussion, seems pretty much to me like shutting the stable door after the horse has been bolt-gunned."
In a lecture, which was peppered with witty remarks, he started off by warning listeners to leave if they were not prepared to hear what he had to say.
"So, if you're not prepared to hear why I think politicians have got the British television industry completely wrong because they peer at it through a filter of their own prejudices, and that's a fact, then get out now," he said.
Iannucci dedicated much of his lecture, called We're All In This Together, to discussing the debate surrounding the BBC, concluding: "Tampering with it is madness."
Iannucci commented on the panel tasked to look at the future of the BBC and criticised the absence of creatives.
"Oh, and no viewers too. Just people from the Executive Branch of television. It's like a car company was looking into what car it should make next, but only spoke to the managers and not to any of the engineers. Or drivers.
"You cannot have a meaningful root and branch review of television, if you're only going to deal with one branch," he said.
Iannucci said the best US shows are modelling themselves on "what used to make British TV so world-beating".
He added: "We have changed international viewing for the better, and I think sometimes our political partners forget this."
He asked why politicians do not talk to creatives, joking: "Is it because we don't wear a tie?"
He added: "Talk to us."
Iannucci hailed British viewers too and said they are "the best audience in the world".
He concluded his lecture saying: "The British are very good at calling out nonsense.
"So, if the British public feel they're being bullsh***ed at, if they get the slightest whiff that what's being done to the BBC is purely political, then I urge the relevant ministers to leave the country - get out now - for they really don't know what's about to hit their fan."