Leader election problem has been studied in the past to improve the efficiency of both distributed systems and wireless ad hoc and sensor networks. Yet, few research has been done on the leader election process for wireless mesh networks. Most of the existing leader election protocols consider wireless networks in general, without focusing on the particularities of mesh networks. Thus, these protocols are not suitable for wireless mesh networks. The lack of research on this issue has motivated us to design a leader election protocol dedicated to wireless mesh networks. In this work, we propose an efficient leader election protocol for wireless mesh network, which is based on the construction of a spanning tree that includes all wireless mesh routers. The protocol elects the node with the longest remaining battery life. In this paper, we give a detailed description of the proposed protocol, prove its correctness, discuss its message and time complexities and then evaluate its performance through simulation using ns-2. We show that our protocol is efficient and scales well with the increase in number of mesh routers and mesh clients.