Controversial news anchor Piers Morgan has reignited his fierce feud with author J.K Rowling - but this time he has offended millions of people around the world at the same time. Following Rowling’s internationally famous Harry Potter series' 20th birthday yesterday (26 June) Piers was lacking in his congratulations.

Piers MorganPiers Morgan did not make many friends after sharing his thoughts on Harry Potter

Upon the anniversary, Rowling tweeted to her legion of fans and said: "20 years ago today a world that I had lived in alone was suddenly open to others. It's been wonderful. Thank you. #HarryPotter20."

Morgan then responded with a feisty tweet of his own and said: "20 years of conning the easily mesmerised masses with execrable literary hogwartwash. Congrats."

MORE: Piers Morgan Slammed For Comments About Ariana Grande

Rowling’s books and her intricate world of Harry Potter and Hogwarts have gained worldwide and have sold a staggering 400 million copies, been translated in 68 languages and made into eight films.

J. K. RowlingJ. K. Rowling's books have become international success

Morgan wore a pair of Harry Potter spectacles and denounced the books as "badly written tosh" on Monday's episode of ITV breakfast show Good Morning Britain.

Morgan and Rowling have been embroiled in bitter disagreements before; however, this appeared to be one step too far for many.

MORE: Here's How Fans Are Enjoying The 20th Anniversary Of Harry Potter

Unsurprisingly, many fans leaped to the defence of the books and railed against the presenter’s outburst.

One Twitter user wrote: "Harry Potter gave a lot of people enjoyment but more importantly hope, you bully," while another commented: "Encouraging the young to get into literature. You're right Piers. She's a disgrace."

The pair have previously clashed over her political views as well as his dislike for her books - in February they were embroiled in a Twitter row about Donald Trump.

Earlier this month, Rowling was awarded The Order of the Companion of Honour in the Queen's Birthday Honours List for services to literature and philanthropy.