New Delhi, Dec. 7: Ratification of the Land Boundary Agreement with Dhaka is unlikely to be taken up this parliamentary session because the Centre is yet to finalise the rehabilitation package for residents of Indian enclaves in Bangladesh who may want to cross over to India.

Ratifying the 1974 India-Bangladesh pact will enable the two countries to exchange enclaves and adverse possessions.

Enclaves are small 'islands' of one country's territory, populated by its citizens, embedded deep inside the territory of the neighbour. These remain largely ungoverned by either country.

Adverse possessions are areas contiguous with the border that one country occupies and administers within the other's legal territory.

India has 111 enclaves in Bangladesh with a population of 37,334, while Bangladesh has 51 in India with a population of 14,215 (according to a July 2011 headcount).

The agreement gives enclave residents a choice - they can remain where they are and switch their citizenship, or they can come over to their mother country.

Most residents of the Indian enclaves are expected to seek resettlement in India after the swap, and their opposite numbers in Bangladeshi enclaves to largely prefer staying back in India and gain Indian citizenship.

Adverse possession residents also have this choice and are expected to stay back and switch citizenship on both sides.

All the Bangladeshi enclaves are in Bengal - in Cooch Behar district - and all the Indians returning from enclaves in Bangladesh will have to be resettled in Bengal, making the state the principal stakeholder in the exchange.

Mamata Banerjee's opposition to any enclave swap had been the main obstacle blocking the pact's ratification so far but she recently gave the go-ahead on condition that the Centre cough up the entire rehab package.

Her government, however, is yet to endorse the suggested package, which the Centre must now work out with her before moving to have the pact ratified.

Sources said the package, which provisionally includes housing under the Indira Awaas Yojana and a onetime cash assistance, can anyway be implemented only after the Bengal government identifies the land for resettlement.

Besides, the Constitution (119th Amendment) Bill to ratify the agreement, introduced in the upper House on December 18 last year, is before a parliamentary panel. It can be taken up for passage only after the committee submits its recommendations and the cabinet clears them.

After passage in the upper House, it will have to be introduced in the Lok Sabha.

Union home secretary Anil Goswami will convene a meeting of his ministry on December 11 to discuss the rehab package. Then he will meet the parliamentary panel.

One other snag before the pact's ratification is the lack of consensus in Assam, a player in the exchange of adverse possessions.

A 2011 protocol - a roadmap for implementing the pact - signed by the two governments provides for redrawing of boundaries to maintain status quo over the adverse possessions.

Under this formula, India will receive 2,777.038 acres of land and hand over 2,267.682 acres, gaining 509.356 acres. Bengal, Assam, Meghalaya, Tripura and Mizoram will be involved in this exchange, with Assam alone losing territory on balance.

Playing politics over the proposed redrawing of the border, the Assam BJP rejected Congress chief minister Tarun Gogoi's repeated pleas last year to accept the agreement. It accused the then UPA government of 'giving away' Assam's territory.

But last week, the state unit was left red-faced when Prime Minister Narendra Modi said during an Assam trip that the pact would be ratified. The Congress immediately accused the local BJP of a U-turn.

'Now we need to explain to the people of Assam that the areas to be transferred are already in possession of Bangladesh and that the handover is merely a formal acceptance of ground reality,' a senior Union home ministry official said.

The foreign and home ministries will jointly push for early ratification of the pact after speaking to the lawmakers and chief ministers of these five states.

For the BJP, hoping to win Assam in 2016, an early resolution could mean a wide enough window to repair political damage from the 'territory transfer'.

On Thursday, Jorhat MP and BJP member Kamakhya Prasad Tasa had a tough time explaining the 'U-turn', eventually saying there was no clash between the national interest and Assam's interests.