It is not thought that Hockey-Morley, a former Abbey National marketing director, has a job to go to.
Since joining the Post Office in 2006, he has helped oversee the launch of several product and service initiatives including its broadband offering and the expansion of its financial services business, a joint venture with the Bank of Ireland.
His departure comes ahead of the planned mutualisation of the state-run Post Office.
Business secretary Vince Cable recently announced that the Government is exploring a John-Lewis style structure “where employees, sub-postmasters and communities get a greater say in how the company is run”.
Prior to the Post Office, Hockey-Morley spent 13 years at Abbey National, most recently as director of marketing and customer retention.
He oversaw the launch of a brand campaign to push the Post Office’s community credentials earlier this year.