The veteran broadcaster David Dimbleby has said a cross-party public commission should appoint the BBC chair, in the wake of Richard Sharp’s resignation after breaking rules over dealings with Boris Johnson – but ruled himself out of the running for the job. Sharp resigned after being found to have breached public appointment rules for failing to declare a connection to a secret £800,000 loan for the UK’s former prime minister. Talking to BBC Radio 4’s Today programme, Dimbleby said the current system gave too much power to prime ministers to select the BBC chair and that a new way needs to be found. “We’re not idiots politically, we know everybody has political views. We know they disagree,” Dimbleby said. “But we look for somebody to run something like the BBC who sets their politics to one side. The best way of assuring that would be to have a commission made up of all parties … and let them decide.” The Sunday Times revealed earlier this year that Sharp had secretly helped an acquaintance, Sam Blyth, who wanted to offer an £800,000 personal loan guarantee for Johnson, during the period Sharp was applying to be BBC chair. Sharp resigned on Friday after an investigation by the commissioner of public appointments concluded he had broken the rules by failing to declare his link to the loan, creating a “potential perceived conflict of interest”. It is still not known who ultimately provided Johnson with the loan, which only became public after he had left office. Dimbleby said it was unclear whether Sharp had misled or should have explained further about his involvement in the loan, but that the affair showed a new way of appointing the BBC chair should be found. Dimbleby also said Johnson “rode roughshod over accepted practices” during his time in No 10 and had leant on the Department for Media, Culture and Sport to get Sharp appointed. Pointing to Johnson’s proroguing of parliament in 2019, Dimbleby said his behaviour had “blown apart” the UK’s political system, which “works by convention and practice and habit and relies on people behaving decently”. He said Johnson’s behaviour showed why the power of the prime minister in choosing the BBC chair needed to be curtailed. When asked if he would be interested in becoming the next BBC chair, Dimbleby ruled himself out of the running. He has previously applied for the role twice unsuccessfully. “I’m now focusing on broadcasting, which has always been my greatest pleasure. So I’ll carry on doing that. And if asked to do it, I’ll say ‘no, thank you very much, not this time round,’” he said. The former BBC journalist Andrew Marr endorsed Dimbleby as a good candidate for the job on Newsnight on Friday evening. He said: “I personally would like to see a really big, experienced proponent of public service broadcasting who would remoralise and lead the BBC in a new way. He will not thank me for saying so, but someone like David Dimbleby is who I’d like to see.”