Greg James has revealed that his father has suffered a stroke, but is "fighting hard."
The BBC Radio 1 presenter, 40, says he plans to start his Comic Relief challenge on Friday (13 March), cycling 630 miles (1,000km) on a tandem bike over eight days across the UK.
James was absent from last Friday's Radio 1 Breakfast show to be with his family after his father had a stroke during a planned heart procedure.
In an update to listeners on Monday, James said he knew his dad would want him to get back on the airwaves and is "still with us" but "fighting hard."