The Common Council shall be the judge of the election and qualifications of its members and of the grounds forfeiture of their office and for that purpose shall have power to subpoena witnesses, administer oaths, and require the production of evidence. A member charged with conduct constituting grounds for forfeiture of his office shall be entitled to a public hearing on demand and notice of such hearing shall be published in one or more local newspapers of general circulation in the city at least one week in advance of such hearing. Decisions made by the Common Council under this section shall be subject to review by the proper judicial authority.