Complex sentence: Collins was not selected as a Sinn Féin candidate for local government elections, in part, due to his public suspicion of the IRA and Sinn Féin leadership, whom he accused of running down'the war'.
Split into simpler sentences: Collins was not selected as a Sinn Féin candidate for local government elections. In part, this was due to his suspicion of the IRA and Sinn Féin leadership, whom he suspected of running down'the war'.