“I must admit I am slightly dreading – make that totally dreading – getting out of bed in the middle of the night to get ready to present the show.
“But I am really looking forward to it.”
Alastair will present alongside Susanna Reid on GMB from Monday 10 to Wednesday 12 May.
It comes after ITV boss Kevin Lygo spoke out on the lack of replacement for Piers recently after his exit, explaining: “Piers is a special thing. You can’t replace somebody like him. There is nobody like Piers, for good or bad.
“We have a roster of presenters, including Ben [Shephard], Susanna [Reid], Charlotte [Hawkins] and Kate [Garraway].
“They’re all stepping up and doing a few more days than they would have done.”