John Lithgow has revealed that he has accepted a role in the upcoming TV adaptation of the Harry Potter books.

After weeks of speculation, the Conclave star has confirmed he’ll play Hogwarts headmaster Albus Dumbledore in the new series.

Speaking to ScreenRant, he admitted that taking on the iconic character was “not an easy decision”.

“It came as a total surprise to me, I just got the phone call at the Sundance Film Festival for yet another film,” the Oscar nominee explained. “And it was not an easy decision, because it’s going to define me for the last chapter of my life, I’m afraid.

“But I’m very excited, some wonderful people are turning their attention back to Harry Potter.”

John added that the thought of staying with the show for seven seasons was “why it’s been such a hard decision”,  remarking: “I’ll be about 87 years old at the wrap party. But I’ve said yes.”

However, the news hasn’t been well-received by everyone, largely down to the fact that the new Harry Potter series will feature heavy input from JK Rowling, whose commentary on the transgender community – which has includedrepeated instances of misgendering trans public figures – has made her a divisive figure in recent years.

Principal actors from the original Harry Potter movies have distanced themselves from Rowling due to comments she’s made about the trans community, including Daniel Radcliffe, Rupert Grint and Emma Watson.

Since the news of John’s casting was made public, many have voiced their disappointment on X (formerly Twitter) about him getting involved with the project, particularly as someone who has previously advocated for the LGBTQ+ community, and was nominated for an Oscar for his portrayal of a trans character in The World According To Garp.

An open letter published in Book Riot, which urged the actor to reconsider the role, has also been widely shared in the last 24 hours…

HuffPost UK has contacted John Lithgow’s team for comment.

Towards the end of last year, US broadcaster HBO – which is producing the Harry Potter series, with one season devoted to each novel – defended JK Rowling’s involvement in the project.

“We are proud to once again tell the story of Harry Potter – the heartwarming books that speak to the power of friendship, resolve and acceptance,” they told Variety.

“JK Rowling has a right to express her personal views. We will remain focused on the development of the new series, which will only benefit from her involvement.”

Further casting news for the Harry Potter series is yet to be announced.