Now though, the terms of those so-called retention bonuses are weakening and firms like Morgan Stanley, Merrill Lynch, UBS and Wells Fargo may be facing another round of broker departures.
In 2012, Sir Stelios railed against what he called "fat cat bonuses" for Easyjet board members, and the year before he campaigned for the removal of one of the directors.
The Labour leader called for the government to impose a tax on bonuses, which he claimed would raise more money than the bank levy introduced by Chancellor George Osborne.
Unveiling Labour amendments to the legislation, shadow financial secretary Chris Leslie called for a review of the levy - and urged the government to introduce an additional tax on bankers' bonuses.