Durrant and brand marketing head Deborah Maxwell are set to fight it out for the most senior comms post, which has been formed to help kick-start a more effective marcoms strategy.
The drive comes in the wake of Gordon Steele's promotion from executive director of customer services to sales and marketing director.
Steele is leading an overhaul of the Post Office's commercial operations and communications is expected to play a central role in the revamp.
The top marcoms post will oversee a 25-strong comms team currently headed by Durrant, which is responsible for comms across the group's employees, internal publications and network of 17,500 post offices.
Full details of the role are yet to be determined, but the post is set to report to Steele.
A Post Office spokesman said media relations and agency support are not likely to be affected. But it is believed 50 jobs are to be axed across sales and marketing, making way for a raft of senior appointments to lead functions within the restructured department.