NEW DELHI: Top leaders, industrialists, economists and celebrities on Friday descended to witness the launch of landmark GST at the historic Central Hall of Parliament which opened for a midnight ceremony for the first time in two decades.President Pranab Mukherjee, who piloted the first constitutional amendment for unifying more than a dozen central and state taxes, shared a specially erected dais in the circular hall with Prime Minister Narendra Modi and Vice- President Hamid Ansari.Lok Sabha Speaker Sumitra Mahajan and former prime minister H D Deve Gowda too were on the dais with finance minister Arun Jaitley.Former prime minister Manmohan Singh too was supposed to be on the dais but he on Friday sent a regret letter to the Prime Minister's Office apparently owing to his Congress' party's decision to boycott the "tamasha" (gimmick) launch ceremony.The Parliament building complex was illuminated just like it is done on national festivals such as the Independence Day and the Republic Day.At the stroke of midnight, Mukherjee and Modi pressed two buttons on a glass box decorated with orchids and GST inscribed on it.The pressing of buttons launched the GST and a two-minute video showcasing India's diverse culture and tradition. Mukherjee and Modi warmly shook hands after the launch.Industry doyen Ratan Tata, RBI governor Urjit Patel , Member of Parliament-cum-cinestars Hema Malini and Shatrughan Sinha hogged much limelight with many of the participants greeting them.Haseeb Drabu, finance minister of Jammu and Kashmir — the only state which has not passed the SGST Bill — was also present.When finance minister Arun Jaitley entered the hall, Patel walked up to him to exchange pleasantries.Thereafter, the minister walked up to Tata, former empowered committee chairman Asim Dasgupta and former economic affairs secretary Vijay Kelkar to greet them.Almost the entire council of ministers and MPs from ruling alliance sat in the circular hall along with opposition leaders from the Samajwadi Party, the BJD, the NCP and the JD-U.The Congress, the Left, the TMC and the RJD boycotted the ceremony.NCP leader Sharad Pawar was seated with BJP president Amit Shah in the front row.As soon as former deputy prime minister and senior BJP leader L K Advani arrived, Shah gestured him to take a seat on the front row. Advani then sat between Pawar and Shah.SP's Ramgopal Yadav was seated in the front row, so were Bhartruhari Mahtab of the BJD and AIADMK's A Navaneethakrishnan.Subramanian Swamy, a bitter critic of GST-Network — the IT backbone provider for the new indirect tax regime— was also present at the launch.Former finance minister Yashwant Sinha as also Vijay Kelkar, who had first mooted the concept of GST in a report to finance ministry way back in 2003, were also present at the launch.Tata, who sat on the eighth row initially, was requested by S S Ahluwalia to walk up to the initial rows. Tata then went to sit in the fourth row along with Dasgupta and Kelkar.Media tycoon and Rajya Sabha MP Subhash Chandra, SP leader Amar Singh and Pawar's daughter Supriya Sule were also present at the launch.Among the bureaucrats, commerce secretary Rita Teaotia, DEA secretary Tapan Ray, finance secretary Ashok Lavasa, apart from CBEC chairperson Vanaja Sarna and revenue secretary Hasmukh Adhia were present.Recently retired DEA secretary Shaktikanta Das too was present.Unlike the last midnight event held in 1997 on the occasion of golden jubilee of the independence at a special session of Parliament, it was a gala event at its circular - shaped hall that had been loaned for the launch of the historic reform.Former prime minister H D Deve Gowda too was present on the dais to launch the new taxation system that is set to dramatically re-shape over $2 trillion Indian economy.As if giving representation to regional political parties, former Punjab chief minister Parkash Singh Badal and National Conference leader Abdul Rahim Rather were invited for the event.Former GST council chairman Sushil Kumar Modi, former finance ministers of West Bengal and Kerala Asim Dasgupta and K M Mani, who played crucial role in negotiations for GST, were also present.CEC Nasim Zaidi, Niti Aayog CEO Amitabh Kant, Niti Aayog member Bibek Debroy and chief economic advisor Arvind Subramanian were also present.The GST Bill was originally piloted by Mukherjee when he was finance minister in the previous UPA regime in 2011.The GST Council, that brings together the central and state governments, has met 18 times to thrash out how the tax will work.Originally, the launch of GST which had been in the works for over a decade, was to be done from Vigyan Bhawan — the largest convention centre in the national capital that has hosted majority of the meetings of the GST Council.But the historic Central Hall was thought to be a better choice considering the importance of the new indirect tax code that unifies more than a dozen separate levies to create a single market with a population greater than the US, Europe, Brazil, Mexico and Japan put together.GST will simplify a web of taxes, regulations and border levies by subsuming an array of central and state levies including excise duty, service tax and VAT.It is expected to gradually re-shape India's business landscape, making the world's fastest-growing major economy an easier place to do business.GST has been dubbed as the most significant economic reform since the BJP government came to power in 2014 and is expected to add as much as 2 percentage points to the GDP growth rate besides raising government revenues by widening the tax net.A four-rate structure that exempts or imposes a low rate of tax of 5 per cent on essential items and top rate of 28 per cent on cars and consumer durables has been finalised. The other slabs of tax are 12 and 18 per cent.