The communists backed China in the 1962 war & even today they get pained to see India solving its energy issues. If the deal happens India will have thousands of Megawatts of nuclear power which will enable our industry to cut costs while keeping the pollution levels under check. This means more business, more employment & better quality of life for Indians. There won't be many POOR & HUNGRY left to vote for the communists.
The victory of the communists lies in keeping the country backward & unstable.