Comedian Russell Brand has cancelled his remaining tour dates - including a Blackpool show next week.
The controversial comedian's mother Barbara Brand was involved in a road accident last week, prompting him to cancel some shows.
Now, as she remains in a critical condition, a spokesman for the Opera House, where he was due to play on Thursday, May 10, has said: "We regretfully announce the indefinite postponement of his remaining tour dates.
"Tickets will be refunded via their point of purchase."
The Re-Birth tour has been running since last April, with much of the show centred on his own experience of becoming a parent.
The star has posted a video on Twitter, telling fans: "My mum's been in a really serious road accident and has sustained what are called poly-traumatic injuries, that means numerous, life-threatening injuries.
"So, I won't be able to do the rest of my Rebirth tour. If you've got tickets, they'll be refunded or possibly rescheduled but I can't really imagine that and I certainly can't imagine performing at the moment, because I feel too sad and too connected to this.
"I apologise but obviously it's circumstances beyond my control."
Barbara Brand, 71, was taken to hospital after she was badly injured in a hit-and-run car crash.
In the video, Brand said he realised "the importance of people you love".
And he added: "I'm sad for my mum. She's vulnerable and she only finished chemotherapy a month ago. For her to be in this situation already is very difficult..."
He praised the NHS, saying 'to see the way the medical professionals operate is phenomenal. We should be really grateful for the NHS. I think of it as the soul of this country...'.
Brand said he would be off 'social media for a while', adding: "Thank you for all your positive, beautiful messages."
Barbara Brand was travelling in the back of the comedian's chauffeur-driven Audi A8 when it collided with a Vauxhall Astra near Brentwood, Essex, on Thursday morning, according to The Sun.