Prime Minister Narendra Modi on Sunday led a BJP charge against the Congress for "callously" giving away Katchatheevu island to Sri Lanka, slamming it as yet another "anti-national" act of the party for which the country is still paying the price.

With the issue having a resonance in Tamil Nadu whose fishermen often bear the brunt of Lankan action against their alleged intrusion into its waters, Congress president Mallikarjun Kharge hit back asking why the government did not act to take back the island in its 10 years in power and termed Modi's attack as poll-eve desperation.

Modi seized on a media report - based on an RTI reply Tamil Nadu BJP president K Annamalai received on the decision of the then Indira Gandhi government in 1974 to hand over the territory in Palk Strait to the neighbouring country - to target the Congress, an ally of the state's ruling DMK.

"Eye-opening and startling! New facts reveal how Congress callously gave away Katchatheevu. This has angered every Indian and reaffirmed in people's minds- we can't ever trust Congress," he said on X, sharing the report.

Modi added, "Weakening India's unity, integrity and interests has been Congress' way of working for 75 years and counting." He raised the matter later at his rally in Meerut and linked the issue of the capture of Tamil Nadu fishermen and the seizure of their boats by the Lankan forces to the island treaty.

Reacting to the charge, Kharge said the island was given to Sri Lanka as part of a friendly agreement in 1974 and reminded the government that it too had undertaken a similar "friendly gesture" towards Bangladesh with an exchange of border enclaves.

"Pradhan Mantri Narendra Modi ji, You have suddenly woken up to the issues of territorial integrity and national security in your 10th year of misrule. Perhaps, elections are the trigger. Your desperation is palpable," he said in a post on X.

In the past, Modi has raised the issue in Parliament as well, while noting that the Tamil Nadu government often writes to him over the issue.

The BJP is hopeful that the issue will come in handy in its efforts to gain political traction in the Dravidian territory during the Lok Sabha polls, more so as it involves neighbouring Sri Lanka whose treatment of its own Tamilian citizens and Tamil Nadu fishermen has long been a charged political issue in the state.

In his Meerut rally, Modi said one more "anti-national" act of the Congress has appeared before the country.

The island was with India and was very important from the point of view of security, he asserted.

However, the Congress claimed that it was of no use and "cut off a part of Maa Bharti" and separated it from the country, he charged.

The country is still paying a price, the prime minister said referring to the capture of fishermen and their boats when they go near the island.

He said, "It is a consequence of the sins of the Congress that our fishermen are still getting punished." Home Minister Amit Shah said the decision of the Indira Gandhi's government showed that the Congress is against the unity and integrity of India.

He said on X, "Slow claps for Congress! They willingly gave up Katchatheevu and had no regrets about it either.

"Sometimes an MP of the Congress speaks about dividing the nation and sometimes they denigrate Indian culture and traditions. They only want to divide or break our nation," he said.

Union Minister Nirmala Sitharaman said Tamil Nadu's ruling DMK should stop its "misinformation" on the Katchatheevu issue.

"...What the RTI reply has revealed has been stated authoritatively by former CM Jayalalitha Amma in the TN state assembly itself," she said on X.

Responding to the allegations, DMK Organisation Secretary R S Bharathi said the prime minister has "no achievements" to showcase and charged that he was only spreading "lies." Bharathi said in 1974, the DMK held state-wide agitations and public meetings to oppose and condemn the ceding of Katchatheevu to Sri Lanka.

The DMK's position has been made amply clear multiple times by late party patriarch M Karunanidhi and party president M K Stalin. The DMK was out and out against giving away Katchatheevu to the neighbouring country, Bharathi said.

BJP spokesperson Sudhanshu Trivedi said Tamil Nadu fishermen used to go to the island earlier but the agreement India signed with Lanka under the Indira Gandhi government barred them from doing so.

Unfortunately, neither the DMK nor the Congress is raising the issue, but Modi is due to his commitment to the issues pertaining to the country and its people, he said.

Another BJP spokesperson Shehzad Poonawalla took a swipe at Congress leader Rahul Gandhi over his claim at the opposition INDIA bloc rally in Ramlila Ground that Modi has resorted to "match-fixing" for the polls by targeting opposition parties.

Poonawalla said, "Some people are talking about match-fixing. In 1974, the Indira Gandhi government, compromising the country's national interest and the interest of the people of Tamil Nadu, handed over Katchatheevu island to Sri Lanka to benefit the Congress' first family...Rahul Gandhi ji, your family had done a deal-fixing." The BJP spokesperson also accused the Congress of letting Aksai Chin go into the illegal occupation of China and a portion of Jammu and Kashmir into the illegal occupation of Pakistan.

The media report cited by BJP leaders also quoted first prime minister Jawaharlal Nehru's comments on the issue, then a source of dispute between India and Lanka, that he would have no hesitation in giving up claims on the island.

In a dig at Rahul Gandhi, Trivedi asked why the Congress leader is keeping mum on the issue and said that he should tell people that not only his party but his family too is responsible for this.

Except for the headline, this story has not been edited by The Telegraph Online staff and has been published from a syndicated feed.