Pretty much the title. I have a contract with some people who have to sign it to make it official. By what descriptive noun do I refer to these people? "Presumptive signatory"?
They are parties to a contract and, depending on the type of contract, they are called lessor/lessee, buyer/seller, grantor/grantee, etc.
They are the potential signatories (in fact, before signing the document, they are not even parties to the contract, because it has not yet been executed and is therefore not effective).