The BBC as it is presently run and organised may be unable to deliver its public service remit in reflecting different viewpoints, cultures and opinion, according to Samir Shah, one of the corporation's non executive directors and an independent producer.
Shah recommends more radical devolution, with the BBC broken down into a federation of regional and national operations, BBC2 relocated to Birmingham, and the organisation turned into a publisher broadcaster, like Channel 4.
He says the "One BBC ethos" unwittingly creates a "monolithic posture that makes it appear anti competitive".
That, in turn, is weakening its ability to nourish a plural society, the conditions in which a mature democracy can thrive.
Shah even raises the question of whether the BBC should be the sole beneficiary of the licence fee in future.
His views are contained in a carefully written essay, called The BBC, Viewed from Inside and Out, in a book, The Price of Plurality, published last week.
The essay was published to coincide with an Ofcom and Reuters Institute seminar in London, to debate public service broadcasting and plurality.
In February Shah backed Lenny Henry's complaint that the television industry had failed to tackle ethnic diversity, especially among off screen management, where people tend to appoint and mentor others like them.
Shah, a former managing editor in the BBC news and current affairs division when John Birt was director general, says that if the corporation is to continue to be the sole recipient of the licence fee it needs to work harder at offering real plurality in supply and delivery of programmes and services.
He also vividly contrasts the way the BBC sees itself, and how outsiders do. Within the BBC scale and size is seen as an asset, he writes, because it can be used to target different audiences, catering for them with different services.
Viewed within the BBC these arguments are compelling. But viewed from outside, other factors carry weight too. The idea that the only place where society can speak to itself is via the good offices of the BBC worries many.
"Decision making is in the hands of a handful of people and, pace Lenny Henry, that handful does not yet reflect the world outside the BBC. Its manifold strengths are its weakness. For all its multiplicity of outlets, its range of tone and voice, there is a singular cultural idea that permeates the BBC.
Shah concedes that this idea binds the BBC together, accounts for the genuine sense of shock over fakery and fixing, and drives its triumphs when the nation comes together, such as for Comic Relief.
That same culture, though, informs a deeply held sense of a BBC point of view. And that of course runs counter to the notion of plurality of voice.
Shah concedes that if some of the £4bn a year income from the licence fee and BBC Worldwide's commercial contribution is given to Channel 4 the latter will slowly but surely change, until it becomes little more than a department of the BBC.
From inside the BBC there is a mountain of paperwork produced almost daily that demonstrates how every penny is - one way or another - spent on its public purposes. The BBC argument is that you need all kinds of programmes to justify a universal licence fee... That argument looks more convincing from the inside than the outside.
Shah suggests that the way ahead lies in more radical reform, rather than just moving great chunks of BBC broadcasting and production away from London to Manchester, so it competes within itself to deliver quality.
Such a transformation could place the BBC both at the centre of the national conversation and make it the guarantor of its diversity and plurality.
