Simon Cowell’s “little arrival” is causing havoc in the West End.

The 54-year-old music mogul is expecting his first child with girlfriend Lauren Silverman, who is due to give birth on February 28.

And London musical I Can’t Sing: The X Factor Musical, which is based on his hit TV competition franchise, needs to know the baby’s name in order to successfully debut on February 27.

“The entire show is written and but one of the penultimate scenes, parodying Simon and Lauren’s little arrival, cannot yet be penned. One whole song hangs around the name of the tot,” a source told British newspaper The Mirror.

“There is also a strong chance that the baby’s name is not known for the first few performances – which is a nightmare.”

Funnyman Harry Hill has penned The X Factor Musical script and it is claimed he is freaking out about the production.

He reportedly hopes the baby will come in time for his show to premiere without a hitch.

“Harry knows it needs to be topical,” the insider explained.

“Simon being a dad cannot be glossed over – it’s going to be a dinner-table talking point for months to come.”

Simon isn’t affiliated with the production and he is not required to make an appearance at the opening show.

It is claimed if he chose to be at the front of the theatre for the show instead of with Lauren in the hospital while she is in labour, pandemonium would ensue.

“Lauren would probably have him hung, drawn and quartered if he missed the birth,” the source said.

I Can’t Sing: The X Factor Musical will stage performances at the London Palladium.