Long, who undertook various freelance work after being made redundant by the EA last year, is now director of policy and engagement for the national body.
The role will see him lead on liaison with ministers and officials, comms and stakeholder engagement.
Before his time at the EA, Long was an award-winning news and current affairs producer at the BBC and a government special adviser. He also worked in charity comms.
His appointment comes alongside that of two other directors: Tim Leslie, director of risks and markets, and David Robson, director of corporate and business services.