Ross Kemp updated Dame Barbara Windsor fans on her dementia battle today (June 18).
Speaking on Good Morning Britain, the former EastEnders star confirmed there has been a "marked decline" in the 82-year-old's health.
Doctors have said her husband Scott Mitchell, 57, needs to start thinking about moving her into a care home full-time.
Ross Kemp gives heartbreaking Barbara Windsor update
During an interview with Susanna Reid and Ben Shephard, Ross, 55, said: "Sadly it's going to happen and it's probably going to happen in the nearer future rather than the long-term future.
"There has been a marked decline in her health and this is a disease that has no cure."
Later tonight, Ross presents a documentary on ITV about the reality of living with dementia.
He interviews Barbara's husband Scott who opens up about the heartache of seeing his wife's health deterriorate.
Scott says: "The doctor is basically telling me I need to prepare myself that at some point it may not be sustainable to give her the kind of care she needs at the house.
"It's horrible. It's the thing I've always feared."
Ross hasn't seen Barbara since February due to lockdown restrictions.
Due to her age and health problems, she is in the vulnerable category and so had had not been allowed to see visitors.
The last time he did see her, Barbara, who played his on-screen mum Peggy Mitchell in EastEnders, didn't recognise him.
Ross was left heartbroken.
He said: "The moment that dementia is diagnosed, not only does it have an impact on that person, it's like dropping a ripple, it goes across families and friends.
"If you look at the episode of Scott tonight compared to last week's, that covers from mid February to virtually up until present day.
"Look at the impact it's had on him."
UK's biggest killer
Despite the coronavirus pandemic, dementia is still the single biggest killer in the UK.
Some 850,000 Brits have dementia while 700,000 cared for loved ones with the condition.
"I think the COVID-19 virus has had a massive impact on all of us but in particular that vulnerable bunch of people," Ross added.
"Despite what we've been through, dementia is still the biggest killer in the UK and there is no cure.
"The numbers of 850,000 are set to double in the next 25-30 years."
- Good Morning Britain is on ITV, weekdays at 6am.
- Ross Kemp: Living with Dementia is on ITV, tonight at 7.30pm.
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