He alleges breach of contract and claims that he has been excluded from the rewards of the project. Ball told Building: "As a Cornish man behind a Cornish project, I have pledged the last six years of my life and my practice's resources to this project. I have even risked my family home.
"I hope it will be easy to understand that being excluded from continued participation in the venture, and all the benefits that flow from its successful outcome, has left me deeply disappointed."
The writ claims that in 1997, after three years' work on the £80m project, Ball was relegated to the position of unpaid director, from which he was sacked last summer. The document also claims that, in the same year, the trust agreed to pay Ball £233 000 for his work. However, Ball now wants a share of future royalties from use of the Eden Project trademark.
Ball argues that he and Smit agreed to found the project on a 50:50 basis, sharing costs, rewards and intellectual property rights, although no partnership document was drawn up.
The Nicholas Grimshaw & Partners-designed scheme is due to open next Easter. The Eden Trust declined to comment on the writ.