As a portfolio manager at a large investment firm, you are responsible for implementing investment strategies based on research and projections. Recently, you received access to exclusive research reports from a third-party vendor who provides insights on emerging market trends. However, you discover that this vendor has made significant political contributions to candidates in the recent elections, some of whom may influence legislation affecting your firm's investment strategies.

Considering your role, the CFA Institute's Code of Ethics and Standards of Professional Conduct, and the interests of your clients, how should you address the situation? Discuss the ethical implications of using the vendor’s research, the importance of transparency, and how you should communicate your decision to clients and stakeholders.