Stewart and his legal team will haul the troubled Championship outfit before an FA arbitration hearing tomorrow to claim Leeds owe him the money following a contract dispute.
Stewart joined Leeds on an initial three-month emergency loan from Hull in 2014 with an agreement to make the switch permanent at the end of last season.
The winger agreed terms on a full-time deal and signed his contract, but problems arose when Leeds lodged the contract with the Football League.
League chiefs had to return the paperwork because the authorised signatures on it from Leeds bosses were no longer valid.
Starsport has learned that among those who signed the contract were former managing director David Haigh, who left Elland Road in April following a bust-up with current President Massimo Cellino.
Following his departure from Leeds, Haigh's name was removed from the 'authorised signatures' list held by the League.
But instead of re-signing the contract, controversial Italian Cellino refused and is now claiming the contract is no longer valid.
He pulled the plug on Stewart's deal and the England U20 international joined Ipswich last summer instead.
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But Stewart, 24, who started his professional career at Manchester United, claims Leeds still owe him the difference in wages he is now earning at Portman Road compared to the higher terms he agreed at Elland Road.
Cellino is challenging the claim and is set to incur more legal fees on behalf of the fallen giants.
But the latest revelations are guaranteed to bring more shame and embarrassment on the troubled outfit.
Cellino is still serving a ban from the League as a result of a conviction for tax evasion that prevents him from running the club.
Several influential directors have recently resigned, while boss Neil Redfearn was left stunned last weekend when six of his stars refused to travel to Charlton and claimed they were injured.
Stewart's claim is the latest in a long line of legal claims made against Cellino since he took control at Elland Road 12 months ago.