What is the scope of an action for damages under an agreement for sale of land?

The answer, I think, is that the phrase “under an agreement for sale of land” is broad enough to include an action for damages. Although an action for damages is not an action on the covenant contained in the agreement for sale, the right to damages arises, by operation of law, under the agreement for sale. This point is made by Lord Diplock in Moschi v. Lep Air Services, supra, as follows: The primary obligations of the party in default to perform any of the promises made by him and remaining unperformed likewise to come to an end as does his right to continue to perform them. But for his primary obligations there are substituted by operation of law a secondary obligation to pay to the other party a sum of money to compensate him for the loss he has sustained as a result of the failure to perform the primary obligations. This secondary-obligation is Just as much an obligation arising from the contract as are the primary obligations that it replaces.