"Nepal is now a Secular Sovereign Republic. Best Wishes!
"Successful culmination of long struggle of sacrifice. To People & Leaders of Nepal - Congratulations!
"Warm Congratulations to people of Nepal - It's a big day. #NepalConstitution," the CPI(M) quoted him as saying in a series of tweets.
Nepal had yesterday adopted its new fully secular and democratic Constitution, achieved after seven years of painstaking deliberations, amid violent protests by minority Madhesi groups over a seven province federal structure.