The mysterious reason why Holly Willoughby is not on This Morning

Rochelle Humes will be filling in for the TV presenter

Holly Willoughby has announced she will not be returning to her seat on the sofa for ITV's This Morning on Monday due to her working on 'something else'.

MORE: Holly Willoughby's children give Phillip Schofield surprise birthday gift

The presenter, who normally appears alongside Phillip Schofield on the morning magazine show, revealed on social media that she was instead working on an exciting new project.

In a photo shared on Instagram, the mum-of-three can be seen in her garden relaxing in the sunshine along with a coffee, notebook and her son, Chester, on her back.

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WATCH: Holly Willoughby's children give Phillip Schofield special birthday present

The TV star wrote in the caption: "Vitamin D, caffeine and a side order of distraction from Chester... working on something else next week which I can't wait to share with you all..."

Meanwhile, Holly also took the opportunity to thank her fellow This Morning colleague, Rochelle Humes, for filling in for Holly in her absence. She continued: "Thank you to the lovely @rochellehumes for keeping my side of the sofa warm... x," to which Rochelle responded in the comments: "Got you."

Plenty of Holly's fans took to the comments underneath the post, expressing their sadness about her missing the show and guessing what her exciting new project could be.

MORE: Rochelle Humes looks unreal in slinky black dress – fans react

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Holly usually hosts alongside Phillip Schofield

One person wrote: "Thinking could it be midsummers TV drama? I remember them asking you to join them on the drama and they would see what they could arrange. This was a few weeks ago when you and Phil were chatting to a couple cast members one morning on your show. Good luck whatever it is."

MORE: Holly Willoughby makes surprising fashion change – and fans love it

A second person wrote: "Great Holly. Hope goes well. We will miss you," as a third said: "Happy Sunday Holly... Oh looking forward to the News."

Last week, it was Alison Hammond and Dermot O'Leary who filled in for the week while Holly and Phillip enjoyed an Easter break, and the week before it was former regular presenters Eamonn Holmes and Ruth Langsford. 

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