The support by the TNA once considered close to Liberation Tigers of Tamil Eelam was announced by the party parliamentary leader R Sampathan at a press briefing, saying the former army chief understood the need for an acceptable solution on the Tamil issue better than Lankan President Mahinda Rajapaksa.
"We decided not to support Rajapaksa who is seeking a second term after four years in office," Sampathan said as TNA 'was not satisfied with his assurances on their demands.'
With both Fonseka and Rajapaksa belonging to the majority Sinhala community, the votes of Tamils could tilt the balance.
Fonseka, who is locked in a close contest with Rajapaksa recently visited Tamil dominated areas in northern and eastern Sri Lanka to woo the voters.
Sampanthan said the party had held discussions with both Fonseka and incumbent president Rajapaksa in the recent days to decide on the issue of support for the January 26 presidential elections.
While declaring support for Fonseka, the TNA also issued a nation wide appeal to the Tamil community to back his candidature.
The party was of the opinion it could not support Rajapaksa at the polls considering his past performance as a president and asked the Tamil community to support Fonseka for presidency.
He asserted Fonseka was not in the military anymore and that the TNA was not supporting a 'military official' for the presidency.
The TNA chief also said that his party during talks with president Rajapaksa, had impressed upon the need to remove all the high security zones in the north but had not received a favourable response on the matter.
Sampanthan said, there was no 'agreement' signed with Fonseka before rendering him support.
The document handed over to the TNA by Fonseka recently, among other things, commits the retired general to lift the state of emergency (in vogue since August 2005) in the country at the earliest.
It calls for release all the persons who are in detention without any evidence within one month of coming to power. The document demands grant of general amnesty to those who were engaged in war activities and help in their rehabilitations.
The document handed over by Fonseka to Sampanthan also calls for full restoration of all institutions of civil administration. It demands that securities forces would be stationed at strategic locations only, taking into consideration national security and that the high security zones would be dismantled in keeping with forces re-location.