With Sonia Gandhi's son-in-law Robert Vadra coming under daily attack from Narendra Modi over his controversial land deals, senior Congress leader Digvijaya Singh has challenged the BJP to file a police case.
Mr Singh's dare followed senior BJP leader Arun Jaitley's statement to NDTV last week that Mr Vadra was a symbol of misuse of power in 10 years of Congress rule.
"Mr Arun Jaitley is a very smart lawyer. If Robert Vadra has violated the law, what has stopped the BJP and him from filing an FIR (First Information Report) I am daring him. Let Mr Arun Jaitley file an FIR against Robert Vadra," Mr Singh said on NDTV's "Political Roots", as he took questions from first-time voters at Indore's Daly College.
"Vadra has broken no law, if he has, he will not be shielded by the Congress. Let Modi first explain his links with Adani," he added, referring to allegations that Mr Modi, the chief minister of Gujarat, gave vast tracts of land to the Ahmedabad-based Adani group at dirt cheap rates.
Mr Vadra is married to Mrs Gandhi's daughter, Priyanka. He has been accused of making a fortune through sweetheart land deals in Congress-ruled states like Haryana and Rajasthan. The Congress lost Rajasthan to the BJP in last year's state elections.
In October, the Supreme Court rejected any investigation into Mr Vadra's land deals, saying that a person "can't be called a sinner merely because he is linked to a politician."
Last night, the BJP's Uma Bharti repeated her threat to "throw Robert Vadra in jail."
While campaigning in Jhansi, from where she is running for Parliament, Uma Bharti said, "Even if my party colleagues get angry with me, if it comes to me, I will send the son-in-law to jail."
When Ms Bharti said this last week, Mr Jaitley had said, "Agencies will decide who goes to jail not politicians. You don't spare anybody, you are not vindictive on anybody."
The BJP sharpened its barbs at Mr Vadra after a Wall Street Journal article last weekend detailed how, with no experience in property development, he amassed a large real-estate portfolio during the decade that the Congress has been in power.
At a rally in Chhattisgarh on Sunday, Mr Modi, the BJP's prime ministerial candidate, sneered at Sonia and Rahul Gandhi, saying "Look at this magician, this is the mother-son model, mother-son's business. I've heard of 2G, now I've also heard about 'jijaji (brother-in-law)'."