The resolution adopted by Tamil National Alliance (TNA) aims to have the federal solution included in the current constitution-making process.
The government headed by President Maithripala Sirisena and Prime Minister Ranil Wickremesinghe has already launched a process to formulate a new Constitution for the country replacing the 1978 statute.
The Tamil demand for a federal solution dates back to the days when Sri Lanka, then Ceylon, came to be granted independence by the British in 1948.
With the defeat of the LTTE in 2009, the Tamil leadership has adopted a softer approach to give up on the separatist demand.