Sarah Ferguson will get a “substantial amounts of money” for the deal, according to Handmade – the group behind films such as Withnail and I, Time Bandits and 50 Dead Men Walking.

The deal comes amid mounting speculation over the duchess’s finances after it emerged that her US firm, Hartmoor, is expected to close before the end of the year with debts of about £600,000.

Handmade plans to turn her children’s books Tea For Ruby and Little Red into animated series.

It has also signed her for a six-part series with National Geographic re-tracing the journey of great women explorers.