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.
“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.
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.
