You may not have noticed but the BBC's latest trust scandal has effectively shut down Scotland's independent television production sector.

RDF, the company that furnished the BBC controller Peter Fincham with the doctored footage of the Queen, owns pretty much all the Scottish action, since it bought up IWC Media (Relocation, Relocation) and the Comedy Unit (Still Game), our largest independent producers two years ago. Now, because of the Queen scandal, BBC and ITV have frozen any new commissions from RDF.

IWC had itself been created out of a merger of Kirsty Wark's company Wark Clements and the former Sunday Herald columnist Muriel Gray's outfit, Ideal World. They were formerly Scotland's biggest producers - but they eventually sold out to the London-based RDF because it was the only way to ensure that they would get commissions from London channel controllers. I think there is a kind of pattern here.

But it gets worse. In 2008, I'm told, STV is going to be allowed by Ofcom, the industry regulator, to shut down much of its Scottish generated non-news programming. Something to do with digital switch-over and the coming of a Gaelic TV channel. I have great respect for the Gaelic tongue and wish it well, but it is no substitute for a quality service that the vast majority of Scots can understand.

However, it looks like closedown for Scottish broadcasting. Network commissions from the four terrestrial channels (BBC, ITV, Channel 4, Five) have halved in the past three years from 6% of total UK spend to around 3%, according to the regulator, Ofcom. That's a loss of something like £40m a year. The BBC should be spending around 9% of its UK budget in Scotland, on a population basis, but it has been spending 4%. If I didn't know it better, I'd think it was trying to tell us something.

The creative industries in Scotland - which depend massively on the big TV companies - are simply being wiped out. Producers, writers, directors, actors, editors, camera crews, make-up artists and set designers have all had to go off to London to get work. Or Cardiff or Birmingham. Scotland used to be proud of its broadcasting and creative sector - not anymore. It's going the way of the electronics industry.

This shrinkage raises all sorts of political questions. Blair Jenkins, the former head of news and current affairs at BBC Scotland, revealed in this column in June that spending on current affairs in Scotland has been cut by 45% and news by 27% in the same period. He resigned in disgust - and all credit to him. At a time when Scotland is taking greater charge of its own destiny through devolution, it was an act of cultural vandalism on behalf of BBC bosses.

Now, this doesn't just mark the end of a great tradition of Scottish film and television making, which goes back to the days of John Grierson and Lord Reith. It's not just that we are losing our stake in one of the key industries in the post-industrial economy, one which, according to the DCMS recently, is worth more to the UK than financial services. No, the creative clearances also pose the most fundamental challenge to Scottish society: if there is no medium which authentically reflects Scotland's culture and politics, how can we conduct a coherent national conversation? If we see ourselves through the distorted prism of a London media, how do we know who we are? And how do we talk to the world instead of just to ourselves?

I will be accused of being parochial for saying all this, but the truth is that the only conversation that matters now is the one that takes place in the West London postal districts. There is no cohort of knowledge workers in the world more narrow-minded and parochial than the London media village. Broadcasting in Britain is increasingly run by a handful of metrocentric solipsists who have completely lost touch with reality outside the M25.

At the recent Ofcom conference on public service broadcasting in the nations and regions held in Cardiff, they revealed their contempt for anyone outside the loop. The ITV chief executive, Michael Grade, said that Scotland just "didn't have the talent" anymore. The director-general of the BBC, Mark Thompson, said that Scotland simply "wasn't coming up with any ideas". Tough old world. Big boys' game.

This is patronising nonsense. I spent more than 20 years in the BBC - half in London, half in Scotland - and in my experience there was just as much creativity in Scotland as in London, and a lot more energy. But that creative drive was constantly frustrated by lack of funds and the pull of the south. As soon as you reach a certain level in Scotland - in broadcasting and many other fields of professional life - you simply have to go where the jobs are, which is London. Some come back, but precious few.

This magnetic attraction of London has become all the more powerful since public service broadcasting capitulated to the market. The BBC used to be a countervailing force to metropolitan centralisation; but now it has become an agent of it. Yet the market doesn't exist in a vacuum. The broadcasting industry is conditioned by politics - by the funding it gets from the public purse and by the regulatory regime established by government. If the politics is right, the market will follow. In fact, speak to most people in the creative industries in London and they say that Scotland is a fantastic place to do media business - it's just that there's no business anymore. If you want to get commissions, you have to do it in London.

Well, the time has come to put an end to all that. Scotland cannot allow its most important cultural institutions to be ripped off by people who cannot be trusted to uphold ethical standards or to understand the imperatives of public service.

The Scottish political system has to be deployed to redress the balance and revive Scotland as a creative force in the world. The first step must be the Scottish Parliament taking on responsibility for broadcasting. It makes no sense that this is a reserved power, except in the minds of paranoid Unionists who believe that BBC Scotland is a Nationalist plot. I'm sure that Gordon Brown, who is in giving mode, would respond to a clear expression from Holyrood that this is a function which should properly be exercised in Scotland.

Then there has to be a regulatory regime established which doesn't have the metrocentric blindness of Ofcom. The Scottish government also needs to lobby the BBC, north and south, to remind it of its charter obligations and its public service remit. Oh, and there's the cash that goes to STV for all those public information slots.

The BBC has just opened one of the most advanced broadcasting facilities in Europe, in Pacific Quay. It would be nice if it found something useful to do in it. And it makes no sense for network news bulletins, transmitted in Scotland, to continue to be dominated by the politics of a parliament which no longer has jurisdiction over Scottish domestic affairs.

This is a matter of profound importance to everyone living in Scotland; for every business and for every citizen. Nearly three years ago the former First Minister, Jack McConnell, promised in his St Andrew's Day address that Scotland would become a "global hub" of the creative industries. Nobody laughed; they would now.