The Attorney General shall be the legal adviser of the Department and shall upon request of the Department institute injunction proceedings or any other court action to accomplish the purpose of this chapter. In the prosecution of any criminal action by the Attorney General and in any proceeding before a grand jury in connection therewith the Attorney General may exercise all the powers and perform all the duties which the solicitor would otherwise be authorized or required to exercise or perform and in such a proceeding the solicitor shall exercise such powers and perform such duties as are requested of him by the Attorney General.