The People says Mackay has called the managers' union into his bitter battle to get a £2million pay-off from Tan.
The Scot wants his contract honoured in full despite Tan giving him a quit-or-be-sacked ultimatum. Tan, at Anfield yesterday to watch Cardiff lose 3-1, thinks Mackay should walk away unpaid.
But the Scot has brought League Managers' Association chief Richard Bevan into the crisis.
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