Princess Eugenie pregnancy: Sarah Ferguson confirms her daughter's due date

Posting on Instagram in January Eugenie said: "We’re so excited to share that there will be a new addition to our family this summer."

Eugenie revealed the news alongside a a photograph taken by her husband, showing her son August embracing her and kissing her bump in a field.

Her mother, the Duchess of York has now revealed in an interview that the baby is due is in the coming days.

"We don't know what it is yet. But the baby is due by the end of May, I think. So it's any minute now," Sarah told Hello.

During the interview Prince Andrew's ex-wife described herself as "one of the best grannies ever", as she thinks "like a three-year-old".

Last month Sarah said she loves being a grandmother and said her grandchildren find her "very funny".

"It's a whole new phase of life and I am modelling myself on Super Gran," she told OK! Magazine.

"I love being with them and how it brings out my inner child. My grandchildren seem to find me very funny. I love indulging them, too."

Sarah has also revealed that she is set to launch a podcast, "Tea Talks with the Duchess and Sarah".

She said it will be "about the highs and lows of everyday life" and would see her "taking on some of the biggest and strangest stories from around the world".

In a post shared on Instagram announcing the news, she wrote: "Long-time friends and tea fans, author Sarah Ferguson, Duchess of York, and Sarah Jane Thomson, entrepreneur and founder of First News, will be getting to the bottom of week’s talking points while enjoying a soothing cup of tea.

"They learn about themselves, each other and give their take on some of the biggest and strangest stories from around the world.

"No topic is off the table. No biscuit will remain undunked."