Last Night's Viewing: Bank of Dave, Channel 4

As Barclays' headhunters begin their search for a new chief executive, it seems unlikely that they will cast their net wide enough to find Dave Fishwick, a minibus dealer from Burnley. I suppose you can't really blame them: Dave hasn't got an awful lot of banking experience, and while he's a self-made millionaire who owns a cherry-red Ferrari and a helicopter with his name on it, his knowledge of credit instruments is rudimentary at best.

Still, it's a shame. Dave Fishwick might not be a career banker, but he has some pithy insights that the industry could stand to hear. "The bastard banks!" he snorts, slamming his car door, as Bank of Dave begins. "Fifty billion quid! How can you lose 50 billion quid and still pay bonuses?"

It's a good question, and one we'd all like answered. Being an entrepreneurial sort, though, Dave's response isn't limited to a critique of the current model; instead, he's planning to institute a new one. He's going to start his own bank, a people's bank, a single branch in Burnley offering market-leading interest rates and common-sense loans to local people who have seen their credit dry up since the financial crisis hit. Dave, who is irrepressible in the same way a fire engine is red, makes it sound simple.

It is not, in fact, simple at all. As a series of slightly shell-shocked-looking experts explain, Dave hasn't got a cat in hell's chance of opening a bank; besides anything else, he'll need £10m to guarantee deposits. (Banks, we are told in a phrase rich with post-Libor irony, are "tightly regulated by the Financial Services Authority"). At first, this doesn't particularly bother Dave: "Sometimes it's far easier just to go and do something than to get permission," he says. He tries to get Richard Branson's phone number. He tries to get Mervyn King's phone number, by calling directory inquiries, and asking to speak to Mervyn King at the Bank of England. He installs a cash machine and a safe and clocks set to New York and Burnley time on his £100-a-week premises, and presses doggedly on with an application for a licence that he is never going to be granted.

Only when one of his advisers awkwardly points out that if he refers to his enterprise as a bank without permission "it might be straight to jail" does reality begin to seep in. And wow, do we feel the unfairness on his behalf. Dave Fishwick is one of the most irresistible documentary heroes I've ever seen: boundlessly energetic, generous, optimistic, eccentric, and funny; unweighed-down by the world, able to wear his success lightly but not apologise for it, and blessed with a knack with people that makes everyone he comes across want him to succeed. He is exactly the sort of person I would like to be running a bank.

Most importantly of all, millionaire though he is, he still feels like the little guy. Two moments in particular: a visit to a career banker, who informs him that he should beware of having "ideas above his station"; and an encounter with a seven-year-old boy gazing longingly at his Ferrari, who Dave invites to sit behind the wheel, and who listens attentively as our hero tells him firmly that if he works hard enough he can have one himself one day.

The gods do appear to smile on Dave a bit. He at least gets a licence to lend money, so that even if he can't look after other people's cash, he can at least give them his. It seems a curious banking model, particularly when he hands over several thousand pounds to a tropical fish merchant who would vaguely like to buy a couple of sharks, but it's certainly more charming than the Bob Diamond approach. It is hard, above all, to imagine that when Mr Diamond gets a rare piece of good news from the FSA, he fishes a banana from his pocket to celebrate. "'I was saving this for later," says Dave, a man with a Ferrari who can be made happy by a piece of fruit.

Twitter: @archiebland