Channel 4’s deputy chairman has gone on the attack again, bashing Rupert Murdoch and News Corporation for the amount of power they wield in British media. On Sunday Puttnam, former CEO of Columbia Pictures, gave an interview to the Observer newspaper, calling for UK business secretary Vince Cable to block News Corp from owning BSkyB outright. Puttnam warned the BBC this afternoon that a unified Murdoch empire would have a single voice penetrating newspapers, TV and e-readers. Puttnam described News Corp’s voice as a “clear right-of-centre corporate notion, run by middle-aged white men, of the way the world should be”. Puttnam told Radio 4’s Media Show that Murdoch’s influence among British politicians comes from the way his newspapers can sway the 1-2% of the undecided vote that could mean the difference between an MP being re-elected or losing his job. Referring to Murdoch being spotted going into the back entrance of 10 Downing Street for a secret meeting, Puttnam said: “When you find a senior politician and a newspaper tycoon in secret conclave, democracy is in peril.” News Corporation declined to comment.

Before Puttnam gets carried away, it’s worth remembering that there are regulatory controls in place to ensure impartiality in UK TV news coverage. The UK Competition Commission has also given Sky News a clean bill of health in terms of undue Murdoch influence. Plus Sky News only accounts for 4.9% of total UK TV news viewing, small in comparison to public service TV news providers such as the BBC and ITN, which services ITV and Channel 4. “Even if – and it’s highly speculative — News Corp was to turn Sky News into a UK Fox News, there would remain a high degree of plurality and diversity in the market for news provision,” one insider tells me. What’s interesting is why, after years of keeping his head down, has Lord Puttnam – never a friend of News Corp and its ambitions — decided to go on the attack now?