Senior Congress leader P. Chidambaram on Thursday slammed the Modi government as India's GDP growth for the first quarter of the current fiscal ended June slowed down to 5.7 per cent, calling it a "catastrophe"."Our worst fears have come true. Sub-6 per cent growth is a catastrophe," Chidambaram said on Twitter."The slide in economy continues. Slow growth, low investment and no jobs. An explosive cocktail," he added.Chidambaram said: "GDP (Gross Domestic Product) and GVA (Gross Value Added) figures are more evidence of Dr Manmohan Singh's indictment of 'monumental mismanagement'."One per cent decline in GDP is a loss of Rs 1.5 lakh crore. Two per cent decline is a loss of Rs 3 lakh crore," the former finance minister further added.India's GDP growth for the first quarter of the current fiscal ended June slowed down to 5.7 per cent, from 6.1 per cent reported for the fourth quarter of 2016-17, official data showed on Thursday.