Such city and county acting through the respective governing bodies of such municipality and county shall have the right to lease such hospital upon such terms and for such a length of time as they may decide, or to sell the same; provided, however, that no such leasing or sale shall be final or valid unless and until it has been approved by a majority of the qualified electors of such county and city voting on such question at an election called for that purpose, subject to the provisions of section 34-106, Idaho Code.