John Simpson, the BBC’s world affairs editor for more than 30 years, has said he turned to writing fiction because he was being eased out of his job for being old.

Simpson, 74, one of the most familiar faces on British TV news, claimed his previous boss at the BBC, a “very clever” man, wanted him out.

“He decided that people like me, I wasn’t the only one – you know, David Dimbleby and John Humphrys – were what was wrong with the BBC. I could have told him what was wrong with the BBC.

“They started pushing me out and I was too dopey to realise what was going on for quite a long time. The fact that all my ideas got turned down and I wasn’t on air and my pay was being rapidly and alarmingly cut back.

“When I did finally realise, I thought I’m going to have to earn some money in some other fashion so I started writing this novel.”

Simpson was speaking to the Cheltenham literature festival about his newly published spy thriller, Moscow, Midnight. He did not name the previous boss, although he was referring to the former Times editor James Harding, who was director of news between 2013-18.

Simpson was so bruised that his novel became all about the “foul BBC” and its machinations and he was looking forward to causing trouble.

Then he heard Harding was leaving and being replaced by a “blessed friend … a wonderful, wonderful” woman who saved him.

The appointment of Fran Unsworth led to some rewriting. “It doesn’t take place at the BBC, it takes place more or less at Sky News.”

Simpson’s novel delves into the murky, violent world of Russian espionage and he was looking forward to it being revelatory.

“I was really annoyed actually about all the stuff in Salisbury. I wanted this book to be a bit of an eye opener for people about how the FSB and the GRU operate.

Everybody knows now, he said. “It certainly has made it easier for people to accept what I’m writing.”

He told the audience that he believed most of the stories coming out about the GRU were being leaked by the FSB because of their rivalry. They want to put “the GRU back in their box”.

Simpson said Russia was a country he liked and that he had respect for Vladimir Putin, describing him as “quite pleasant” in person.

“I think he is a most fantastic politician who is operating from a position of great weakness.”

Simpson said the Russian economy was below Australian, with seven times the people. “Most people would think Russia is a superpower again and of course it isn’t at all. You’ve got to admire the ability of a man like that.”

Simpson said having a younger wife and a 13-year-old son helped keep him in touch with how things are in the modern world.

Almost everything in his novel is based on real events and real people and Simpson said he had been accused of hankering after the good old days, the time of licentious, hard-drinking reporters.

It was not true, he said. “I was never a bottom pincher… and I never got pissed at lunchtime but lots and lots of people did. It was a different world and a worse world.”

Simpson said he had started on a second novel. “It is a parachute from when I get the boot from the BBC.”