Holly Willoughby would quit 'This Morning' if Phillip Schofield left.
The duo have fronted the ITV show together for over a decade, and now the 38-year-old presenter revealed the pair have always agreed they "wouldn't want" to work on the programme if they're not side by side.
Appearing on 'Shopping With Keith Lemon', she said: "We said right from the beginning that if either of us didn't do it, we wouldn't want to do it.
"I can't imagine 'This Morning' without Phil."
Her 57-year-old co-host recently opened up about their relationship, and he described Holly as "the sister I never had".
He explained: "We have such a laugh. We're best mates, she's like the sister I never had. I just adore working with her, she's just perfect."
Meanwhile, last month it was revealed both 'Good Morning Britain' and 'This Morning' will be extended by 30 minutes from early January as part of an ITV scheduling shake-up.
The morning news show - featuring the likes of Piers Morgan and Susanna Reid - will start as usual at 6am and run until 9am, half an hour later than normal, from January 6.
'Lorraine' will then begin at the earlier time of 9am until 10am, followed by 'This Morning' - which currently begins at 10.30am - at 10am until its usual finish time of 12.30pm.
Holly and Phillip - who present the brunch-time show from Mondays to Thursdays, with Ruth Langsford and Eamonn Holmes hosting on Fridays - will then hand over to 'Loose Women' for its unchanged 12.30pm to 1.30pm slot.
The duo announced the news on 'This Morning', and were clearly excited about the half an hour extension.
Holly said: "Two-and-a-half hours, yikes! I'll be able to sing and dance and do all sorts of things."
Phillip added: "What fun we're going to have."
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