The BJP on Sunday targeted former Union Finance Minister P. Chidambaram and his family's "undeclared assets in foreign countries", after which the Congress hit back by saying that the BJP had no moral right to ask questions and should instead give answers on various issues.

The opposition party termed the Income Tax (I-T) Department "another caged bird" that does the government's bidding.

Addressing a press conference here, Defence Minister and senior BJP leader Nirmala Sitharaman drew parallels between Chidambaram's case and that of former Pakistan Prime Minister Nawaz Sharif who has been barred from holding public office for life by that country's Supreme Court for not disclosing assets abroad.

Terming it as the "Nawaz Sharif moment of the Congress", she said: "In this (Chidambaram's) case, the parallels are hard to miss. Therefore, I am wondering if the Congress President -- who himself is also out on bail in a financial matter -- will comment and tell people if he is going to investigate one of his senior leaders (Chidambaram) for not disclosing assets held abroad."

Her comment came after the Income Tax department informed a special court in Chennai that Chidambaram's wife Nalini, son Karti and daughter-in-law Srinidhi didn't disclose their foreign assets and investments while filing their income tax returns.

Bharatiya Janata Party (BJP) President Amit Shah, too, attacked Chidambaram and the Congress leadership.

In a tweet, Shah said that under the law dealing in black money, four chargesheets had been filed against Chidambaram and his family for "possessing and operating several illegal assets and accounts in foreign countries".

"The Income Tax Department estimates illegal assets held by UPA's then Finance Minister to be to the tune of 3 billion dollars! This explains why despite the Supreme Court's orders, Sonia Gandhi, former Prime Minister Manmohan Singh and then Finance Minister P. Chidambaram dragged their feet on the formation of SIT. How could they indict their own selves?" Shah tweeted.

He said that the formation of a Special Task Force (SIT) to track and curb black money was one of the first decisions taken by the Narendra Modi government.

Chidambaram hit out at both Sitharaman and Shah. The former Finance Minister taunted that the "buzz in Delhi" was that Sitharaman was soon going to be appointed a lawyer for the Income Tax department.

"The buzz in Delhi is that Sitharaman will be removed as Defence Minister and appointed the lawyer of the Income Tax Department. Welcome to the bar, Sitharaman," tweeted Chidmabaram, a senior lawyer himself.

Taking a jibe at Shah, Chidambaram said that the President of "the richest political party in India was dreaming of billions of dollars".

"Bring the money back (from foreign undeclared bank accounts) and put Rs 15 lakh in the account of every Indian, as promised," Chidambaram said in another tweet.

The Congress, too, lashed out at the BJP and Sitharaman, saying the country's Defence Minister was mostly busy defending her partymen, whenever the opposition questions them, and that the country's defence was "not her priority", nor was she "interested in even talking about Army's welfare or providing resources to it".

"Why are the Prime Minister and the Defence Minister silent on Rs 58,000 crore Rafale scam? In 2018-19, you gave only 1.58 per cent of Gross Domestic Product to defence, the lowest allocation since 1962. The Army has told a parliamentary panel that it has only 8 per cent state-of-the-art equipment whereas 68 per cent is vintage.

"The Army has said that it has no resources to build roads along the China border. The Defence Minister should tell us first what has she done in this regard?" Congress Spokesman Pawan Khera said.

"They (BJP) are not willing to speak on Piyush Goyal and Jai Shah. No word from them on Chhattisgarh PDS scam or Rajasthan mining scam. No explanations on Karnataka mining scam and Vyapam. Do they (BJP) have any moral right to even ask before they answer these questions?" Khera said.

On I-T Department's chargesheets against the Chidambarams, Khera said: "The BJP government has got a big cage that has many different kinds of birds. The I-T Department is yet another caged bird."

An anguished Supreme Court in 2013 called the Central Bureau of Investigation a "caged parrot".

Khera said that Chidambaram's Chartered Accountant has already termed the allegations "baseless" and clarified his client's position and said that the "complaint by the I-T Department will be opposed in accordance with law".

"The Defence Minister only comes out to defend her party and colleagues. The country's defence is not her priority," Khera said as he raised question over National Security Adviser Ajit Doval's son Shaurya Doval running a firm in partnership with a Pakistani national.