The strongest factor the supply manager can use to improve PQR's negotiating position is that there is considerable competition among suppliers. This factor increases PQR's leverage because it implies that the supplier needs to offer competitive terms to win the business. High competition means that if one supplier is not flexible or favorable in negotiations, PQR can consider alternative suppliers who may be willing to offer better terms.
References
* "Negotiation Genius: How to Overcome Obstacles and Achieve Brilliant Results at the Bargaining Table and Beyond," Deepak Malhotra and Max H. Bazerman.
* "Supply Chain Management: Strategy, Planning, and Operation," Sunil Chopra and Peter Meindl.