The "classic tailored dungarees" with a sailboat smocked design on the front panel have sold out in the six-month and 12-month sizes on the company's website.
But mothers prepared to wait for their babies to grow into the outfit can still buy it in sizes 18 months and two years.
"Due to an enormous amount of interest, there will be a waiting time of up to 8 weeks for this item," the website said.
The company's designs "draw inspiration from the forties, fifties and sixties with fine tailoring, beautiful hand smocking, hand embroidery and vintage-inspired prints designed by and exclusive to the brand", according to a statement on the website.
Much like his mother, whose influence on fashion is dubbed 'the Kate effect' after clothing she wears in public frequently sells out, the pint-sized style icon has been causing shopping frenzies throughout the Royal Tour.
Read more: Kate recycles MaxMara wrap dress
Stockists of the novelty kangaroo backpack, which the Duke of Cambridge was seen carrying on Monday after it had been gifted to his son in Sydney, reported the item had sold out hours after the family's airport appearance.
Prince William and Kate with Prince George bound for New Zealand at Sydney International Airport.
The Australian Koala Foundation is one of the stockists of the bag and sold out of its remaining stock of the item on Monday.
CEO Deborah Tabart said the sudden rush of orders for the kangaroo bag, which was selling for £7 (NZ$29), was a result of the Prince William seen carrying one.
But little George's effect on buying power was first seen just three days after his birth.
Read more: Retailers survive the 'Prince George' effect
The £20 printed white aden + anais cloth in which the Duke and Duchess of Cambridge wrapped their baby son before leaving the Lindo Wing of St Mary's Hospital sold out almost instantly.
Prince William and Kate with new-born Prince George. Photo / AFP
- DAILY MAIL
