(a) No advocate and solicitor shall accept a brief if such acceptance renders or would render it difficult for him to maintain his professional independence or is incompatible with the best interest of the administration of justice.
(b) (i) An advocate and solicitor who has at any time advised or drawn pleading or acted for a party in connection with the institution or prosecution or defence of any suit, appeal or other proceedings shall not act, appear or plead for the opposite party in that suit, appeal or other proceedings.
(ii) An advocate and solicitor shall not act unless the consent of the first party for whom the advocate and solicitor acted is obtained in writing and the advocate and solicitor is not embarrassed by so acting.