In the Central Hall of Parliament, on the right of President Pranab Mukherjee sat three dignitaries — Vice-President M Hamid Ansari, Lok Sabha Speaker Sumitra Mahajan and Finance Minister Arun Jaitley. But on Mukherjee’s left were placed only two chairs, which Prime Minister Narendra Modi and former prime minister H D Deve Gowda occupied. There was space for a third, where former prime minister Manmohan Singh, arguably the man who contributed most to the ushering in of the goods and services tax (GST), would have been seated. But the Congress boycott of the midnight ceremony had meant Singh was forced