Subject to the provisions of this Act a petition for dissolution of marriage by a decree of divorce may be presented to the district court by both the parties to a marriage together, whether such marriage was solemnised before or after the commencement of the Marriage Laws (Amendment) Act, 1976 (68 of 1976)*, on the ground that they have been living separately for a period of one year or more, that they have not been able to live together and that they have mutually agreed that the marriage should be dissolved.