Rae's retirement comes at a crucial time in the history of the ACS, with the Office of Fair Trading widely expected to refer the grocery market to the Competition Commission.
However, an ACS spokesman claimed that this would not jeopardise the group's lobbying position when it comes to the inquiry. He said: "David is not leaving tomorrow and once a replacement is found there will be a proper hand-over to ensure the new chief executive is up to speed. In terms of the Competition Commission, public affairs manager James Lowman will be in charge of the campaign."
Rae has spent five years as chief executive and as well as overseeing an increase in membership to more than 32,000 he has played a key role in lobbying the OFT to the point of recommending a full inquiry. He has also helped keep the convenience sector at the heart of talks in tackling underage alcohol purchases and the current campaign against the relaxation of Sunday trading laws.
He said: "I have had a great five years and looking back on this time I believe the organisation has achieved a great deal. I know that I leave ACS in a healthy position to move forward."
The search for a replacement will begin after a board meeting on May 16.