Leave to Serve in Public or Civic Office. Any employee elected or selected for a full-time public or civic office which takes him from his duties with the school system, shall upon proper written request, receive a leave of absence with accrual of seniority, but without pay for the term of such office or two (2) years, whichever is less. Unless such employee returns within the time limit hereinbefore specified, such leave of absence shall terminate unless it has been renewed for a specific period with the approval of the Board. It is recognized that an employee has the right to serve in, or be elected to public office less than full-time. However, such services shall not be permitted to interfere with his normal employment duties.