When a major feature is requested by the project sponsor that significantly impacts the project's delivery date and budget, the project manager should communicate these impacts to the stakeholders. This involves presenting the results of the impact analysis and negotiating for the necessary resources and time to accommodate the new feature. This approach ensures that the stakeholders are fully informed of the implications and can make decisions based on the project's best interest. It aligns with the PMBOK guide's emphasis on stakeholder engagement and communication as key aspects of effective change management1. References: * PMBOK Guide's Change Management Process For PMP Exam1. * Managing Change in Organizations: A Practice Guide2.