The producers of spoof X Factor musical I Can't Sing! have postponed previews for 48 hours to give themselves more time to set up the "hugely ambitious" production.
The show, written by comic Harry Hill, tells the story of a young woman who lives in a caravan with a talking dog and finds fame on the talent show.
Former EastEnders actor Nigel Harman leads the cast which includes characters based on show regulars Simon Cowell, Cheryl Cole and Louis Walsh.
Preview per formances at the London Palladium, scheduled for Thursday and Friday, have been cancelled and the the first show will now go ahead on Saturday.
Producer Rebecca Quigley said: " After much careful thought and discussion, we've decided that we need to take some more time to work on technical aspects of I Can't Sing! at the Palladium.
"As audiences will soon see, the production is hugely ambitious, and the volume of installation and scale of the set means that technical work has taken slightly longer than could have been anticipated to make the show audience-ready.
"We want everyone who comes to see I Can't Sing!, from the very first preview, to have the best possible experience.
"We, therefore, feel that this course of action is the responsible thing to do as producers, both for our cast and production staff at the theatre and for our audiences.
"This is not a decision taken lightly and I'd like to apologise to those who had booked, and indeed sold out, these initial two performances.
"Each and every ticket holder will be offered reseating options and should contact their original point of purchase for further details.
"The entire I Can't Sing! family cannot wait for everyone to see the show and we thank everyone for their patience and understanding."