A risk was identified at the beginning of a project, and a response plan was established. Unforeseen consequences resulted in a higher level of risk. The project manager has an idea that could…

Since the new risk response differs from the original plan and involves unforeseen consequences leading to a higher risk level, it represents a significant change to the project's risk management strategy. It's crucial to involve relevant stakeholders, including the sponsor and potentially the change control board, to review and approve the updated strategy, ensuring alignment and endorsement before implementation.

While management approval is often needed, submitting to 'stakeholders' is a broader and more appropriate initial step for a significant change to a critical plan, as stakeholders encompass all key decision-makers and affected parties.

Implementing a different risk response without prior approval, especially for a significantly higher risk, bypasses formal project governance processes and can lead to unintended consequences.

Using management reserve is a financial decision for unexpected costs, but the immediate action required is to address the response plan itself and seek approval for the new strategy, not just fund it.