2. (b) That's right. An agent's power is not made effectively irrevocable simply by agreeing that it should be so. If it is a term of the agency agreement that the agent's authority is not to be revoked for a specified period, or while particular circumstances exist, the agency power may still be revoked by the principal or renounced by the agent, though potentially giving rise to liability for breach of contract.

An agent's power is only truly made irrevocable (so that any attempt to revoke it is ineffective) in cases where the grant of authority to the agent was made to secure some interest of the agent, in addition to whatever interest the principal may have in the mandate. An example would be where the agency is given as a security for the repayment of a debt owed by the principal to the agent.