arduous

characterized by toilsome effort to the point of exhaustion; especially physical effort; "worked their arduous way up the mining valley"; "a grueling campaign"; "hard labor"; "heavy work"; "heavy going"; "spent many laborious hours on the project"; "

हिमाचल प्रदेश में प्रतिद्वंद्वी दलों के लिए अंदरूनी लड़ाई को नियंत्रित करना एक कठिन काम है।

Curbing internal conflict is an arduous task for rival parties in Himachal Pradesh.