Broadcaster David Dimbleby has criticised Boris Johnson's "attacks" on the BBC, calling them "dangerous".
The former Question Time host, 81, also said he disapproved of BBC presenters who get paid for outside appearances.
He told The Times: "I am very dismayed by the Johnson attacks on the institution. I think they are crowd-pleasing. I think they are quite dangerous. I don't think they will work."
He added: "Margaret Thatcher always had it in for the BBC but she wasn't trying to destroy it ... A lot of people who support Johnson also quite like the BBC. I don't know what is going on in his mind. I think it's quite frightening."
On BBC presenters who get paid for appearances outside the corporation, he said: "If you present the news you shouldn't go off and earn 20 grand for chairing a paint conference."
Dimbleby said the Question Time panels got "less impressive" as "a lot of politicians ... gradually refused to come on" and think, "'What's in it for me?'"
But "it's their duty to explain what they are doing ... To say when you get to the top, 'I am not going to be interviewed', like Boris Johnson did at the last election, is so arrogant ... It doesn't make you a shrewd operator. It erodes the democratic process," Dimbleby said.
Of Downing Street chief adviser Dominic Cummings, he added: "He's like a machine gun ... Shrinking the BBC, getting rid of all the senior people in the civil service, attacking the judiciary ... You don't achieve anything just by attacking them all."
His comments follow reports that Downing Street wants to axe the TV licence fee and fund the BBC through viewer subscriptions.
The Sunday Times previously quoted a senior Downing Street source as saying: "We are not bluffing on the licence fee ... We will whack it."