The veteran broadcaster – whose roles during his BBC career included Europe Editor, North America Editor and presenter of Radio 4’s The World At One and The World This Weekend – took redundancy last month. He revealed his frustrations with the Beeb during an exit interview yesterday with Radio 4’s Feedback programme.
Mr Mardell, 63, said: “We do need to get young people and we do need to get people who feel unserved by the BBC.
“But it doesn’t mean you annoy and dismay your original, basic audience.”
His comments come after the BBC announced in June it would spend £100 million over the next three years on producing “diverse and inclusive content”.
Mr Mardell also hit out at the corporation over its coverage of Brexit and Donald Trump amid major budget cuts.
He said: “If I truly believed that the only fat on the bone, the only thing that could be cut, was reporting and programme budgets then I’d say, ‘That’s a great shame but we’ve got to do it to survive.’
“But is there no other way that the BBC can make cuts?
“Is there nowhere that any of the five or six people that have both ‘Head’ and ‘News’ in their title can look and see other areas where there’s too much fat on the body of the BBC?
“I do worry because reporting is absolutely at the heart of everything we do.
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Mr Mardell admitted he does not “approve of everything that’s being done at the BBC”.
He said: “I think people feel difficult when they leave, some just want to lash out at things that they’ve disagreed with and put up with for 30 years or so.
“Others are overfriendly and don’t want to criticise because they believe in the ethos, as I do, and believe in the licence fee, as I do, and believe in what the BBC’s mission is, as I do.”
On impartiality, which new director-general Tim Davie has warned about, Mr Mardell added: “I think Tim Davie is right in a broader sense that we live in a very partisan world of social media, lots of aggression and bitterness.
“And we also live in a world where, as happens in America, the broadcast media is biased one way or another, and increasingly that is happening here.
“I hope what he is saying about impartiality is a plea for somebody who tries, despite all the difficulties, despite all the hardships, it’s not easy, but to stand above that and say “we are impartial”, not just left or right, he said this she says that, but in a 360 way, exploring all sorts of people’s views.”