Seven aides to Alaska Governor Sarah Palin have reversed course and agreed to testify in an investigation into whether the Republican vice-presidential nominee abused her powers by firing a commissioner who refused to dismiss her former brother-in-law.

Palin, a first-term governor, is the focus of a legislative investigation into her firing of Public Safety Commissioner Walt Monegan a year after she, her husband and key advisers began questioning him about getting rid of a state trooper who had gone through a nasty divorce with her sister.