The Supreme Court will on Monday hear the petition calling for scrapping of the Indus Water Treaty between India and Pakistan.
The plea has been filed by a Delhi-based lawyer M. L. Sharma, who has said that the treaty is unconstitutional.
The treaty was signed on September 19, 1960 by India's first Prime Minister Jawaharlal Nehru and Pakistan President Ayub Khan.
It is one of the most liberal water-sharing pacts in the world.
However, Sharma says the treaty is invalid as it was signed by Nehru and Khan, and that it should have been signed by the President of India.
The agreement covers six rivers - the three eastern rivers of Ravi, Beas, Sutlej and their tributaries and the three western rivers of Indus, Jhelum, Chenab and their tributaries.
Water from the eastern rivers has been allocated to India, and New Delhi is obligated to let 80 percent water from the western rivers flow to Pakistan.
The treaty gives the lower riparian Pakistan more 'than four times' the water available to India.