The 48-year-old, who has been a regular host of the Channel 4 property show since 2004 and also presents the BBC’s Escape To The Country, said he hopes sharing his terminal diagnosis will inspire others to “make the most of every day”.
In an interview with Hello magazine, Jonnie revealed his lung cancer had spread to his brain.
“I don’t know how long I have left,” he. told the magazine.
The presenter revealed the first warning sign of his illness came while he was filming A Place In The Sun in August 2020 in Italy, when his vision became blurry while driving.
“Within a week of flying back from filming, I was being given six months to live,” he said.
“I had to go home and tell my wife, who was looking after our babies, that she was on her own pretty much. That was devastating.
“All I could do was apologise to her. I felt so responsible.”
Jonnie, who shares three-year-old son Rex and two-year-old twins Rafa and Cormac with his wife Jessica, said he had chosen to keep his illness private until now.
Jonnie Irwin with his family
He said: “It’s got to the point now where it feels like I’m carrying a dirty secret, it’s become a monkey on my back.
“I hope that by shaking that monkey off I might inspire people who are living with life-limiting prospects to make the most of every day, to help them see that you can live a positive life, even though you are dying.
“One day, this is going to catch up with me, but I’m doing everything I can to hold that day off for as long as possible.
“I owe that to Jess and our boys. Some people in my position have bucket lists, but I just want us to do as much as we can as a family.”
Jonnie has continued to work as much as possible.
He said: “I don’t know how long I have left, but I try to stay positive and my attitude is that I’m living with cancer, not dying from it.
“I set little markers, things I want to be around for. I got into the habit of saying ‘Don’t plan ahead because I might not be well enough.’
“But now I want to make plans. I want to make memories and capture these moments with my family because the reality is, my boys are going to grow up not knowing their dad and that breaks my heart.”
The TV presenter is also encouraging people to take out life insurance.
He added: “That has helped so much and when I leave this planet, I’ll do so knowing Jess and the boys are in a house that is fully paid off and there’s a bit of money in the bank for them to live off.”