New Delhi, Nov 17 (ANI): The Congress party on Monday commenced a two day long international conference to commemorate the 125th birth anniversary of country's first Prime Minister Jawaharlal Nehru amid much fanfare. While speaking at the event, party President Sonia Gandhi said that Nehru was a leader who gave all his life working for the nation and for the unity and prosperity of the nation. Gandhi said that Nehru always believed that secularism was the main crux of Indian Constitution and that he was always ready to fight against power that would pick up caste based issues in the nation. She also said that the former PM believed that secularism was not just an idea but a necessity for a diverse nation like India. The congress president also acknowledged Nehru's work in putting the path of modernization, industrialization and social reforms. The Congress party has barred the NDA leaders from the event and the invitation was sent to all non-BJP parties. TMC chief and West Bengal Chief Minister Mamata Banerjee, AIADMK supremo J Jayalalithaa and JD (U) leader Nitish Kumar, RJD led by Lalu Prasad Yadav, RLD, JD(S) and leaders of the Samajwadi Party have been invited to the conference.