Embattled Florida GOP Chairman Jim Greer, a right-hand man to and political confidant of Gov. Charlie Crist(R), announced Tuesday he is resigning his post just days before the state party is scheduled to convene and elect a new leader.

Greer’s resignation is viewed as yet another blow to Crist’s Senate campaign. The governor had defended his handpicked chairman and beat back calls for his ouster for weeks.

Crist, who represents the more moderate wing of the GOP, has come under fire from movement conservatives due to his support from the national party in his primary against former House Speaker Marco Rubio (R). Greer’s perceived support of Crist also angered conservatives, who are backing Rubio, and they began calling for his head weeks ago.