Bangladesh's main opposition leader Khaleda Zia has written a letter to Indian Prime Minister Manmohan Singh demanding that India should stop building the Tipaimukh dam in its north-eastern region.
The Tipaimukh dam on the Barak river is in India's Manipur state.
Zia dispatched the letter Monday, The Daily Star newspaper said. The letter was sent a day after India said that it had 'consulted' Bangladesh on the project and would not do anything to harm the environment of the region.
Details of Zia's letter to Singh were not released. The two last met in March 2006, when Zia was the Bangladesh prime minister.
The move by Zia came even as the Sheikh Hasina government prepared to send a parliamentary team accompanied by experts to visit the site of the proposed dam over Barak river.
Part of the Brahmaputra river system, Barak river bifurcates on entering Bangladesh territory and is known as Surma and Kushiyara.
In another move, five environmentalists from India's Manipur state joined their Bangladeshi counterparts to voice their protests at a seminar held in Bangladesh's Sylhet.
The Indian delegation included R.K. Ranjan Sinha of Earth Science Department of Manipur Central University, and environmentalists Ramananda, Joseph Marr, Vikramjit and Arnab Dutta.
Engineer Muhammad Hilal Uddin, coordinator of the Jatiya Tipaimukh Bandh Protirodh Committee accompanied the team to Sylhet.
Sinha said: "We are here to express our solidarity with the Bangladeshi people."
The project is not at all a viable one, he said, adding: "We want Bangladesh to sit with the Indian authorities to discuss the crucial issue. Besides, it is an issue of common rivers and India cannot take decisions alone."
The speakers claimed that 57 percent dams in the world responsible for environmental degradation are in India and China.
At a discussion last Sunday in the presence of Bangladesh Foreign Minister Dipu Moni, Indian High Commissioner Pinak Ranjan Chakravarty said India has "consulted" on construction of the Tipaimukh dam with Bangladesh after having the matter examined by their experts.
"The perception that India has not consulted Bangladesh about building of the Tipaimukh dam is wrong and out of line," he said, adding: "The proposal of the project has been provided for Bangladesh."
"Feasibility and design of the dam has been examined by Indian experts," he told a seminar organised by Bangladesh-India Friendship Society.
Bangladesh and India have in the past sparred over the Farakka dam project over the Ganga river.
The dispute was settled in 1997 when a bilateral treaty was signed during Sheikh Hasina's earlier tenure as the prime minister.