The Corporation Counsel shall institute any suit or proceeding in behalf of the City which he shall deem the interest of the City requires, and shall appear as counsel in all suits, actions or prosecutions which may involve the rights or interests of the City, and defend the officers of the City in suits against them for their official actions, or for the performance of their official duties, or when any estate, right, privilege, interest, ordinance, act or direction of the City is brought in question. He may take such steps and incur such expenses for the carrying out of his duties as he deems necessary.