What is the test for establishing an agreement to agree?

The legal principle being invoked, concerning “agreements to agree,” is discussed in a number of cases. In the leading case of Von Hatzfeldt-Wildenburg v. Alexander, [1912] 1 Ch. 284, Parker J. said at p. 288-289: It appears to be well settled by the authorities that if the documents or letters relied on as constituting a contract contemplate the execution of a further contract between the parties, it is a question of construction whether the execution of the further contract is a condition or term of the bargain or whether it is a mere expression of the desire of the parties as to the manner in which the transaction already agreed to will in fact go through.