The MTA board’s embattled vice-chairman refused to give up his post yesterday — defying Gov. Paterson’s request that he step down from all government-related appointments for his role in the State Police Dirty Tricks Scandal.

David Mack, a wealthy real-estate developer and big-time political donor, is under fire for refusing to testify in a state attorney general’s investigation that found he was appointed to the third-highest position at the State Police solely for political reasons.

A spokesman for Mack said the vice-chairman has “no reason to resign in light of the fact that [he] used his constitutional rights to decline answers to questions, many of which went back to events that took place some 14 years ago.”