NEW DELHI: Former Prime Minister Manmohan Singh on Monday said the demonetisation will have a "very significant adverse effect" on the GDP . He said the upcoming Central Statistics Office (CSO) data, once takes into account the effect of demonetisation, will show further "reverse effect" on GDP."I have said in Parliament about demonetisation having its effect on GDP and, it has already been established. According to Central Statistics Office estimates (for 2016-17), the GDP growth will be 7.1 per cent as against the targeted 7.6 per cent. But this estimate doesn't take into account the effect of demonetisation on the system. If (that is done), you will see a very significant reverse effect on GDP", Dr Singh told media persons after he released the Punjab Congress election manifesto at a function in AICC. Singh also felt demonetisation will be a major issue in the upcoming elections in the States.Punjab PCC President Captain Amrinder Singh, State campaign committee chairperson Ambika Soni, AICC in-charge Asha Kumari party’s chief spokesperson Randeep Surjewla flanked Singh, country’s only Sikh Prime Minister so far, when he released the state Congress election manifesto.Amrinder Singh tried lend additional credibility to his party’s manifesto by stressing that "the world renowned economist Manmohan Singh ji, who is well versed with the developmental issues of Punjab, had kindly gone through the manifesto during its preparation"The former Prime Minister also used the occasion to launch an attack on the Akali-BJP regime which ruled Punjab for the past 10 years. "Punjab has tremendous all round potential but it has not been exploited because of mismanagement by the government in the last 10 years. The fiscal situation has been mismanaged in a manner which is unprecedented," Manmohan Singh said.Calling upon the people to vote back a Congress government in the State, Manmohan Singh said the party manifesto contained a forward looking developmental agenda."This manifesto is a visionary document which promises to the people of Punjab that we will undo the damage done by the government in the last 10 years..It points to the tremendous potential of Punjab in agriculture, manufacturing, services, infrastructure."Singh also patted Congress de factor Chief Ministerial candidate Amrinder Singh who he described as "a visionary leader" whose "wealth of experience and leadership" Punjab needed for develop and progress.