When can a defendant claim that he was deprived of effective assistance of counsel during the plea process?

When a defendant claims that he was deprived of effective assistance of counsel during the plea process he is, unlike claims of ineffective assistance during trial, not required to show that the result was "unreliable," or "fundamentally unfair" in order to demonstrate prejudice. See Blaylock, 20 F.3d at 1466 ("although Blaylock has received a fair trial, he is not precluded from showing prejudice"). To demonstrate prejudice arising from ineffective assistance in the plea process, the defendant need only "show that there is a reasonable probability that, but for counsel's errors, he would not have pleaded guilty and would have insisted on going to trial." Hill v. Lockhart, 474 U.S. 52, 59 (1985).