Panaji, Jan 2 (IANS): A Goa-based NGO on Monday demanded that Chief Minister Manohar Parrikar withdraw his letter to Karnataka BJP leader B.S. Yeddyurappa promising to consider the southern state's demand for drinking water from the Mhadei river on "humanitarian grounds".

"The Chief Minister should withdraw the letter written to Yeddyurappa immediately. The act of Parrikar is extremely suspicious and against the interests of Goa vis-a-vis the Mhadei dispute," S.N. Joshi, Convenor of NGO Ami Goykar, which serves as an umbrella for various green groups that have been vocal about the Goa Chief Minister's controversial letter to Yeddyurappa told reporters here.

Goa, Karnataka and Maharashtra are currently battling a dispute over the controversial Kalsa-Bhandura dam project across the Mhadei river at a central tribunal.

Mhadei also, known as the Mandovi river, is known as a lifeline in the northern parts of the state.

It originates in Karnataka and meets the Arabian Sea in Panaji in Goa, while briefly flowing through the territory of Maharashtra.

While the river runs 28.8 km in Karnataka, it flows 81.2 km in Goa.

The southern state has demanded that Goa should allow the transfer of over seven TMC water to tide over its irrigation and drinking water needs. The matter is being heard by the Mhadei Tribunal appointed by the central government.

The Goa government has been opposing the Karnataka's demand for over two decades. But last month, Parrikar in a letter to Yeddyurappa, a key figure for the BJP vis-a-vis the upcoming Karnataka polls, had offered to consider the state's demand for "drinking water" on "humanitarian grounds".

Parrikar's letter has evoked criticism from the Opposition as well as civil society groups in Goa.