Budget 2018: Former Prime Minister and economist Manmohan Singh has found little merit in the Union Budget of India 2019 presented by Finance Minister Arun Jaitley on Thursday. The former PM, who has been the most influential voice against PM Narendra Modi's economic policy decisions like Demonetisation and GST rollout, was especially critical of Modi government's promise to double farmers' income by 2022. This was also talked about by Jaitley in his Budget speech yesterday. However, Singh said, the promise if a "hollow assurance". \u201cThe government says farmers\u2019 income will be doubled by 2022. But it\u2019s not possible until the agricultural growth is 12 per cent. Until we achieve that \u2026 It is just a hollow assurance,\u201d Senior Congress leader Ghulam Nabi Azad quoted the former PM as saying after a meeting of opposition parties in Delhi on Thursday. The former PM also said, "fiscal deficit seems to have increased." On Thursday, Singh told NDTV in an interview that he didn't think that the budget was "motivated" by electoral mileage. However, he was worried that "fiscal arithmetic is at fault." Jaitley announced a number of initiatives to with an aim to "double farmers' income by 2022." One of the decision was to set the Minimum Support Price (MSP) for all hitherto unannounced crops of Kharif at least at 1.5 times of their production cost. "This historic decision would prove an important step towards doubling the income of our farmers and NITI Ayog in consultation with Central and State Governments will put in place a foolproof mechanism so that farmers will get adequate price for their produce\u201d, the Finance Minister said in his speech. READ | Budget 2018 benefits, impact LIVE: \u2018Modi Care\u2019 hogs limelight, Jaitley\u2019s proposals get mixed reactions Jaitley said the Centre is promoting organic farming in a "big way." He said, "Organic farming by Farmer Producer Organizations (FPOs) and Village Producers\u2019 Organizations (VPOs) in large clusters, preferably of 1000 hectares each, will be encouraged." The finance minister also announced the development and upgradation of existing 22,000 rural haats into Gramin Agricultural Markets (GrAMs). On Thursday, Singh had walked up to Jaitley and greeted him for presenting the Budget. Singh's purported remarks against the Budget comes months after he had blasted the Centre's decision to implement demonetisation in November 2016 and rollout GST last year. READ | Budget 2018 real estate: 3 hits and 4 misses by Arun Jaitley on property tax The same day, Congress leader Sonia Gandhi appealed opposition parties to unite on issues of "national importance" inside the Parliament and outside. Chairing a meeting of 17 non-NDA parties, Gandhi said all opposition parties should "adopt a common approach and strategy both inside and outside Parliament" against the NDA government over issues affecting sections like farmers, Dalits, youth, poor, women. She also said that opposition parties should be "alert" on the violence in the name of caste and religion.