Ken Clarke has claimed the Tory press office tried to keep him away from the television cameras during his time in government, even attempting to prevent him from going on Question Time.
"I had a great row with them [Conservative press officers] when they told the producer of Question Time that I was ill and they were able to provide a replacement," Clarke said during an interview with the Observer.
" It never occurred to them that I could ring up the producer. She said: 'I'm told you are ill.' After that, I got even more freelance."
The former minister admitted there was "constant friction" between himself and David Cameron, saying his views sometimes "didn't coincide with No 10's".
More top news
The Labour leader did not say whether he would maintain Britain's nuclear deterrent programme.
Ukip leader Paul Nuttall also said he would want to get rid of Sharia courts.
Over 40,000 people picked up their packs to take part in the annual marathon in the capital.