In Matter of Kisloff v. Covington, 73 NY2d 445, 539 NE2d 565, 541 NYS2d 737 [1989], the Court of Appeals rejected the People's post-judgment effort to vacate a plea that had been accepted at a time when all parties were laboring under the misimpression that the crime to which the defendant had pleaded was a class E felony when, in fact, it was a class A misdemeanor. As a result of the error, the defendant's request to be resentenced as a class A misdemeanor had to be granted, and the People were deprived of the benefit of the plea bargain to which they had agreed.