New Delhi: The Congress on Monday stepped up its attack over Amit Shah's son Jay Shah's business demanding resignation of the BJP chief and Rahul Gandhi bringing Prime Minister Narendra Modi in the line of fire accusing his government of practicing crony capitalism.

Congress seeks Amit Shah's resignation over spike in turnover of son's firm, BJP hits back Amit Shah. Pic/PTI

The Congress also sought a probe into the "sudden spurt" into the turnover of a company belonging to Jay Shah by a two-member commission of Supreme Court judges, questioned the timing of the closure of Jay Shah's company weeks before demonetisation and the move of Additional Solicitor General Tushar Mehta deciding to fight the case for Jay Shah.

The BJP hit back accusing Rahul Gandhi of being anti-progress and terming Congress as "sultanate of corruption." Party leader Smriti Irani also said that Jay Shah's business was perfectly legitimate and legal and rejected allegations of crony capitalism.

She accused the Congress of attempting to divert attention "from their own scams and misdeeds."

Uttar Pradesh minister Siddharth Nath Singh also took potshots at Rahul Gandhi, saying "this leader fails to come out of his diaper as he does not even pay attention to the fact that the company he is referring to had closed before demonetisation".

The BJP had on Sunday rubbished the allegations and Jay Shah issued a statement saying the article carried by the website 'The Wire' had made "false, derogatory and defamatory imputations" against him.

The Congress offensive on Monday had a national footprint with Rahul Gandhi leading the attack in Gujarat during his tour of the election-bound state and the party holding press conferences at New Delhi, Lucknow and Jaipur. The Kerala unit of the party also issued a statement.

Gandhi spoke to enthusiastic crowds in Nadiad district of Gujarat and took pot shots at the Modi government.

"When it comes to helping, they help only a handful of industrialists. For 10-12 years, Amit Shah's son's company had nothing, but started earning only after 2014. 'Ajeeb duniya hain' (It's a strange world).

"He (Jay Shah) started with Rs 50,000, and in a year it jumped to Rs 80 crore. This is 'Start Up India', 'Make in India'," he said, mocking the Prime Minister's pet schemes.

"Complete my sentence, 'Na khaunga, Na khaney dunga. Kahan gaya chowkidar? Ye hain Gujarat ki sachchai (I will not indulge in corruption, nor let others indulge in corruption. Where is the gatekeeper? This is the reality of Gujarat)," Gandhi added, as the cheering crowds repeated after him.

He also made a tweet, describing Jay Shah as "Shah jada" and asking Modi if he was "chowkidar" (gatekeeper) or bhagirdar (participant)" in the former's fortunes.

Congress leader Anand Sharma held a press conference in the national capital and asked why Temple Enterprises, a firm owned by Jay Shah, shut down four weeks before the November 8 demonetisation.

"We are not levelling any allegations (of criminality) in this. But it should be made public which commodities were exported/imported by Jay Shah's firm Temple Enterprises and to which countries so that they earned Rs 51 crore from foreign countries and their turnover swelled by 16,000 times," he said.

On Sunday, Congress leader Kapil Sibal said at a media briefing that Temple Enterprises had recorded losses in 2012-2013 and 2013-2014 of Rs 6,230 and Rs 1,724, respectively but showed a profit of about Rs 18,000 in 2014-15.

But the following year (in 2015-16), the company's turnover jumped to Rs 80 crore, he said.

Sharma said it was " beyond comprehension" why persons who had raised company's turnover 16,000 times in a year would suddenly decide to shut it down.

The Congress also continued to raise questions over Rs 10.35 crore loan given to Kusum Finserve, a company owned by Jay Shah that dealt in shares and stocks before getting a contract to build a 2.1 MW windmill in Madhya Pradesh.

"We request the Prime Minister to break his silence over this issue and constitute an inquiry commission consisting of two sitting judges of the Supreme Court," the Congress leader said.

"We are not levelling any allegations. And for the sake of fair and impartial inquiry, Amit Shah must resign as the BJP President as well as from the Rajya Sabha," Sharma said, adding that former BJP chiefs including L.K. Advani, Bangaru Laxman and Nitin Gadkari had resigned in the wake of allegations against them.

Irani, in a statement, said the Congress aggression against Jay Shah was "clearly off tack". "Jay Shah's business is perfectly legitimate and legal. TDS is paid, loans are repaid and company closed after losses. Does this reek of cronyism?" she asked.

"Instead of seeking answers on 80 crores of transactions that are within the purview of the law, it would be more prudent for the Congress to give an account for the more than 80 scams and the Rs 1,80,000 crore that India has lost due to corruption and cronyism of successive Congress governments," she said.

She alleged that the Nehru-Gandhi family "was pressuring banks to give loans to Vijay Mallya in return of airline upgrades is now questioning others."

Irani said Congress attempt to divert attention "from their own scams and misdeeds will not work" and added that "people of India comprehensively rejected the Congress' 'Sultanat' of Corruption".