A letter & # 39; written & # 39; by Winnie the Poe is expected to raise a maximum of £ 6,000 at the auction.
The note was penned 85 years ago on relief stationery by Pooh illustrator E H Shepard in response to an invitation from a birthday party of an 11-year-old boy to a fictional bear.
It is secured with spells, to make it authentic, and a drawing of a screaming Poe with his friend Piglet and was sent to the son of pioneer for birth control Marie Stopes, who & # 39; s a distant friend of & # 39 was an illustrator.
The note is addressed to "Buffkins," because Dr. Stopes' son, Dr. Harry Stopes-Roe, became known as a child.
It reads: “We are sorry that we can come to your party on March 30, but we will be gone. Thank you very much for inviting us. "
The letter will be sold by the Stopes-Roe family and will be for sale on June 24 at Dominic Winter Auctioneers in Cirencester, Gloucestershire.
Auctioneer Chris Albury said: "It's such a charming Winnie the Pooh collection that will be favored by thousands of Pooh and Piglet fans of all ages worldwide.
"The Marie Stopes family connection is also interesting and the friendship between Shepard and the birth control pioneer and their son will be great news."
Under the same hammer also go two pencil drawings, signed and dated in July 1929, with five-year-old Christopher Robin-lookalike Stopes-Roe climbing a tree and riding a pony.
Each drawing is expected to raise between £ 1,500 and £ 2,000.
Stopes-Roe was a well-known humanist and was married to the daughter of illustrious scientist, engineer and inventor Sir Barnes Neville Wallis. He died in 2014.
Shepard, who died in 1976, was an illustrator for Punch magazine for 50 years, though he remains best known for his Pooh illustrations.