Delhi Police on Monday beefed up security outside Sushma Swaraj's residence in Delhi but the foreign minister faces relentless attack on the issue of her role in Lalit Modi controversy.

The genesis of the controversy was disclosure of emails showing that she had spoken to Indian-origin British MP Keith Vaz and its High Commissioner James Bevan favouring the grant of travel documents to Lalit Modi to go to Portugal, purportedly for his wife's cancer treatment in June last year.

Modi, who is wanted in India, has made London his home since 2010 to avoid a probe for alleged foreign exchange regulation violations in the T20 cricket tournament held in South Africa in 2009. The previous UPA government had revoked his passport and had pressed for his extradition.

According to British media which quoted leaked emails, Vaz cited Swaraj's name to put pressure on UK's top immigration official to grant British travel papers to Lalit Modi, who subsequently got the documents in less than 24 hours.

"Congress will demand resignation of Swaraj and PM should himself ask resignation if allegations are true," said Congress leader Shakeel Ahmad. The Congress has also demanded a probe into the incident. Senior leader Digvijaya Singh said, "Shocked by allegations levelled against Sushma Swaraj. She should take moral responsibility and quit. PM Modi must intervene in the matter and order a probe."

Another Congress leader Sachin Pilot said, "PM Modi must intervene in the matter and order a probe. If allegations against Sushma are true, she must step down. We all know that Lalit Modi is a known criminal offender. Why was Sushma Swaraj in touch with Lalit Modi? The Modi government's doublespeak has been exposed."

Janata Dal United leader KC Tyagi said, "Sushma Swaraj must come clean on why she helped Lalit Modi. We condemn Sushma Swaraj's intervention to help a criminal like Modi."

Taking a dig at the Modi government, the Aam Aadmi Party said that 'ache din' has arrived for Lalit Modi. "Lalit Modi will come back to India as he is very close to the BJP. 'Ache din' for Lalit Modi have certainly arrived," said AAP's Rahul Mehra.

"If there are grounds of 'compassion', normal course should be followed, govt should give papers. Why does he need to go to external affairs ministry?” Brinda Karat said.

Senior advocate Prashant Bhushan on Monday called for Sushma Swaraj's resignation while also urging the authorities to look into the creation of a 'conflict of interest' law.

"Sushma Swaraj interceded with the British government at a time when her daughter was Lalit Modi's lawyer," Bhushan said.

However, Manoj Jha of the RJD said person like Sushma Swaraj should not be demonized so early, matter should be investigated properly.

 Sushma Swaraj on Sunday admitted to helping controversial IPL founder and enforcement directorate offender Lalit Modi with his travel documents, but made it clear that she did so only on humanitarian grounds.

Sushma’s explanation
Sushma Swaraj tried to clarify her position in her tweets on Sunday. "Sometime in July 2014 Lalit Modi spoke to me that his wife was suffering from cancer and her surgery was fixed for 4th August in Portugal," Sushma says, adding, "he told me that he had to be present in the hospital to sign the consent papers."

"Taking a humanitarian view, I conveyed to the British High Commissioner that "British Government should examine the request of Lalit Modi as per British rules and regulations. If the British Government chooses to give travel documents to Lalit Modi that will not spoil our bilateral relations," Sushma tweeted.

Sushma Swaraj further said that she said the same thing to Keith Vaz, when he called on her. "I genuinely believe that in a situation such as this, giving emergency travel documents to an Indian citizen cannot and should not spoil relations between the two countries," Sushma said in one of the tweets.

Justifying her stand on the issue, she said "a few days later, Delhi high court quashed UPA government's order impounding Lalit Modi's passport on the ground that the said order was unconstitutional being violative of fundamental rights and he got his passport back."