The Wanted star Tom Parker has revealed he has been diagnosed with a brain tumour which is "inoperable" and "terminal".
The 32-year-old has begun radiotherapy and chemotherapy in the hope of prolonging his life.
Parker and his pregnant wife, Kelsey Hardwick, who have a 15-month-old daughter together, said they want to raise awareness.
The singer wrote on Instagram that "there's no easy way to say this but I've sadly been diagnosed with a brain tumour and I'm already undergoing treatment...
"We are all absolutely devastated but we are gonna fight this all the way.
Hey guys, you know that we've both been quiet on social media for a few weeks and it's time to tell you why. There's no easy way to say this but I've sadly been diagnosed with a Brain Tumour and I'm already undergoing treatment. We decided, after a lot of thought, that rather than hiding away and trying to keep it a secret, we would do one interview where we could lay out all the details and let everyone know the facts in our own way. We are all absolutely devastated but we are gonna fight this all the way. We don't want your sadness, we just want love and positivity and together we will raise awareness of this terrible disease and look for all available treatment options. It's gonna be a tough battle but with everyone's love and support we are going to beat this. Tom and Kelsey xxx
A post shared by Tom Parker (@tomparkerofficial) on Oct 11, 2020 at 11:08pm PDT
"We don't want your sadness. We just want love and positivity and together we will raise awareness of this terrible disease and look for all available treatment options.
"It's gonna be a tough battle but with everyone's love and support we are going to beat this," he said.
James Argent, Gemma Merna and Rebecca Adlington were among the stars sending him messages of support.
Reality show star Argent wrote: "We love you Tom! We got this brother, No doubt about it!"
Olympic swimmer Adlington commented: "Sending so much love and support always."
Actress Merna said: "Sending you and your beautiful family so much love and support."
Sarah Lindsell, chief executive of the Brain Tumour Charity, said: "Over the weekend Tom Parker shared the devastating news that he has been diagnosed with a brain tumour.
"Our hearts go out to Tom, his wife Kelsey and young daughter and their family and friends. Everyone who has been touched by a brain tumour will know just how hard this must be for them.
"We stand with everyone whose lives have been turned upside by this cruel disease and are committed to finding a cure so that no other family has to hear those devastating words."
Parker told OK! magazine that his wife was unable to be in the hospital with him when he was given the diagnosis, because of Covid.
"They pulled the curtain around my bed and said 'It's a brain tumour'...
"I was in shock. It's stage four glioblastoma and they've said it's terminal. It was a lot to deal with by myself. I still haven't processed it."
Hardwick told OK!: "They rang me and told me over the phone. They said 'It's a tumour and it's worst-case scenario.'
"They also told us it was inoperable and what the treatment would be. I was in a complete state."
Asked about her pregnancy, she said: "To be honest, I think I've forgotten I'm pregnant. It's all about Tom at the moment. In four weeks' time (when their baby is due) it obviously won't be, but the whole thing has consumed us."
The Wanted formed in 2009, with Parker, Max George, Siva Kaneswaran, Nathan Sykes and Jay McGuiness.