Ellie Goulding is reportedly planning to invite Sarah Ferguson to her hen do in London

The Duchess of York became good friends with Ellie after they met through the royal's daughter Princess Eugenie - whose father is Sarah's ex-husband Prince Andrew - and Ellie believes the "wild" 59-year-old royal will be a hit with her friends as she is a "rebel and a strong female".

A source told The Sun newspaper's Bizarre column: "Ellie knows Sarah can be wild when she gets going and is so much fun to be around.

"After spending more time with Fergie, Ellie thinks she'll be the life and soul of the party.

"Some of her mates think it's a bit weird that they'll be hanging out with old Fergie at the bash but Ellie is sure she'll be a hit with her guests.

"Fergie's a rebel and a strong female, which Ellie loves. It's going to be one hell of a party."

Eugenie is believed to have introduced the 32-year-old pop star to her fiancé, as she worked with the businessman's father in New York.

Eugenie and Ellie are often spotted out frequenting the Chiltern Firehouse in London's affluent area of Marylebone, and Sarah and her other daughter Princess Beatrice have joined them from time to time.

Ellie attended Eugenie's wedding to husband Jack Brooksbank last October, at Windsor Castle, and even got up to perform for the couple at the The Royal Lodge after-party.

The 'Close To Me' hitmaker will be able to spend more time with her royal pals soon as after she gets married, she and Caspar will be moving to London permanently.

The couple got engaged last August, after 18 months of dating, and are planning to return to her home country after splitting their time between New York, where the art dealer works for Sotheby's, and the British capital.

She said previously: "It's too hard, him living there and me living here - too many flights. But for the first time the long-distance thing feels more OK because we know we're gonna be together when we're married."

In December, Ellie said that other than the engagement ring - which is over 100 years old - they had no plans set in place for their wedding yet, but she admitted Caspar is the more "organised" partner.

She said: "Nothing too serious has been chosen or discussed. My partner's very involved and incredibly organised, way more logistical than me, so we make a good pair."