Guwahati, Jan. 19: Seventy-eight lakh trees will be chopped as part of the forest clearance process for the 1,500MW Tipaimukh hydroelectric project in Manipur, an exercise that Prime Minister Manmohan Singh says will be taken up for “national interest”. The project, which has been in the eye of controversies following opposition from Bangladesh, has received support from the Centre, which has promised not to take any steps that would adversely affect the neighbouring country.