Himachal Pradesh Chief Minister Virbhadra Singh on Friday targeted BJP President Amit Shah over the meteoric rise in the revenues of his son's company, a year after the party came to power at the Centre.Virbhadra Singh, charged by the CBI with holding assets disproportionate to his known sources of income, lashed out at Prem Kumar Dhumal, BJP's chief ministerial candidate for the November 9 election in the hill state, saying his party's main achievement was "ease of doing corruption"."Dhumalji, your remarks on BJP's supposed fight against corruption made me laugh. Last time, I saw your own sons were out on bail," the Chief Minister tweeted."Your party's (the BJP) main achievement is 'ease of doing corruption'. Amit Shah and son's miracle of 16,000 times lucre hike happens only in BJP rule."According to a report on The Wire news website, Temple Enterprises, a company owned by Jay Shah, reported a 16,000 per cent increase in its turnover at Rs 80.5 crore in 2015-16 from a meagre revenue of Rs 50,000 and a profit of Rs 18,728 in 2014-15. The company is involved in the business of exporting agri-products.Virbhadra Singh said the BJP had launched personal attacks on him because it was fearing his government's "real vikas (development)" in Himachal Pradesh."Let's not forget the time when your party chose a joyous day of the wedding of my daughter, Himachal's daughter, to carry out a CBI raid," he added.Virbhadra Singh's response came after Amit Shah and Prime Minister Narendra Modi sharply criticised the Chief Minister over the Congress poll manifesto vowing zero tolerance on corruption if the party retains power in the hill state.""Singh 'saheb' is claiming there will be zero tolerance against corruption. Can anyone believe him? Can you digest it?"The Congress has become a laughing club. Their Chief Minister has a corruption case against him. He is out on bail. Nothing is left for them and they have lost their hold from every part of the country," Modi told an election rally in Kangra in Himachal Pradesh on Thursday.