Cummngs hit back at Morgan after the ex-GMB host criticised him for not allowing Tory MPs to appear on the show.
Osbourne infamously left "The Talk" after defending Morgan on-air.
The viewing figures for the 'Strictly Come Dancing' launch show plunged to their lowest in 11 years.
Ofcom ruled that Morgan was 'entitled to say he disbelieved' the Duke and Duchess of Sussex.
Piers Morgan has been shortlisted for the Best Presenter award, five months after walking out on 'Good Morning Britain'.
The journalist had symptoms including cold sweats, coughing and 'alarming' chest pains.
The former 'GMB' presenter dubbed the Sussexes 'Prince Poison and Princess Pinocchio' in his latest royal rant.
The broadcaster called out the prime minister for not making himself more presentable.