And finally… ‘A royal princess could bring in £1bn to UK economy over her lifetime’

That’s according to Professor Joshua Bamfield, director of the Centre for Retail Research, who says fashion retailers would be the main beneficiaries.

He said: “I think there will be an immediate boost of around £80m when the baby is born, with around £20-£25m spent on souvenirs and the rest on food and drink such as cake and sparkling wine. There isn’t as much excitement when it’s the second baby, but a girl would have the potential to boost the fashion industry.

“As well as the boost to baby clothing sales that we have seen from Prince George, a Princess would be able to set trends throughout her life, which will be great for the people who designed her clothes or those who can make quick knock-off copies.

“It might even provide the impetus for people to start up whole new companies.”

Her Majesty’s Treasury is joined by The Duke of Cambridge who said before the birth of Prince George that he was hoping for a girl but the Duchess of Cambridge wanted a boy.

Prince George’s birth two years ago boosted the economy by £247m, and while the levels of excitement are lower this time around, a sister for him would bring in far more cash in the long term.

Regardless of the royal baby’s gender, The Royal Collection Trust has already announced it will sell an official range of royal baby souvenirs, likely to include plates and cups, through its gift shops in royal palaces and online, the Telegraph has reported.

Other companies, including the pottery firm Emma Bridgewater, are working on their own commemorative mugs and souvenirs.