KATHMANDU: The main opposition leader and CPN-UML Chairman KP Sharma Oli strongly criticised the ruling CPN Maoist Centre and Madhes-based parties for bringing out a Constitution amendment proposal, which the opposition has been claiming to be against national interests. Speaking at a mass demonstration programme organised by opposition parties at the Pradarshani Marga of Kathmandu today, Oli said they were acting against the nation to fulfil interests of some external forces. The event was organised to show the strength of opposition bloc against the government's plan to amend the Constitution. Arguing that the proposal would not serve interests of Nepali people, the immediate past Prime Minister reminded that it was strongly protested in the proposed Province No. 5 as the Province was being split. The leader also criticised that the Madhes-based parties were actually working to destroy the native identity and languages of the region though they claimed to promote the same. He cited that the parties were trying to establish Hindi as an official language so as to belittle Maithili, Bhojpuri and Abadhi languages being practised in the plains for centuries. Oli also claimed that the Madhes-centric parties were not legitimate forces to represent issues of the Madhes as they did not have sufficient votes from the region. Speaking before Oli, CPN-ML General Secretary CP Mainali, Rastriya Janamorcha Chairman Chitra Bahadur KC, Nepal Workers and Peasants Party lawmaker Prem Suwal, Nepal Pariwar Dal Chairman Eknath Dhakal, Nepa Rastriya Party lawmaker Laxman Rajbanshi among others had also criticised the government and ruling parties for registering the Constitution amendment bill. They also said the parties would not let the bill get endorsed from the House. Earlier, the party cadres held taken rallies from various places of the Valley to the main event venue.