Measuring 4ft 6in (1.37m), the urns were supplied in 1935 to replace decaying ones on the parapet of a portico designed by John Nash in 1805.
Witley Court was eventually devastated by fire in 1937.
Estimated at £25,000-40,000, the group will go under the hammer at Summers Place Auctions' garden statuary and ornament sale, in association with Sotheby's, at Billingshurst on May 22.
Contact 01403 331331.
