Ever since Ashley Thomas was accidentally hit by Victoria’s car on Emmerdale this summer, the village vicar’s health has been on the downturn.

Ashley collapsed and was rushed to hospital, where he was later diagnosed with epilepsy. But Ashley’s medical nightmare didn’t end there, when his memory became muddled, causing all kinds of chaos.

Now, after taking a memory test, Ashley is about to receive some terrible news when he’s referred to a hospital specialist. In a heartbreaking new storyline, Ashley will be diagnosed with Early Onset Vascular Dementia.

“It’s the best storyline I’ve ever been given in my life as an actor,” John told What’s on TV. “When I was asked, I said to Emmerdale’s producers, ‘Let’s do it!’ But at the same time, I am aware of taking on the responsibility of a big storyline like this. It’s not just a great story, it’s an incredibly relevant story, and one which touches so many people.”

Devastated by the diagnosis, Ashley must find the right time to tell his family the news. But can he bring himself to tell partner, Harriet, when their relationship has been going so well?

“As Ashley is a vicar, he will have visited homes where people have dementia,” explained John. “He will know the full weight of what is going to happen and in particular what happens to the people who have to give up their lives to care for their loved ones. So he doesn’t even know if that is fair to ask Harriet to do that. It’s very difficult.”

John recently confirmed he was leaving Emmerdale after 20 years.

Watch the interview with John Middleton, above.

Don’t miss the heartbreaking scenes in Emmerdale on Thursday, November 19 on ITV.