CPI-M General Secretary Sitaram Yechury on Friday said that B.R. Ambedkar's vision of the "Constitution above all" was under threat and called upon the people to take forward his ideals."B.R. Ambedkar's vision, more than just symbolising social justice, helped create a political framework to achieve it, and that is our Constitution," Yechury said on social networking sites on the occasion of Ambedkar's 126th birth anniversary."That vision is under threat today. On Ambedkar's birth anniversary we must pledge to take forward the finest lessons from his struggle," he said."Puthandu, Vishu, Poila Boishakh, Baisakhi, Rongali Bihu, Vishuba Sankranthi ... -- one land, many festivals," Yechury wrote."On the day we are marking Ambedkar's birth anniversary and observing Good Friday, let us renew the pledge to cherish and strengthen our unity, protecting this diversity," added Yechury.