In a major boost to bring peace in strife-torn Sri Lanka, Liberation Tigers of Tamil Eelam (LTTE) on Sunday dropped its demand for an interim administration and announced it would allow political parties to function in its strongholds in the North and East, saying that its ultimate aim is to enter ‘‘political mainstream.’’‘‘It is the ultimate aim of the LTTE to enter the political mainstream,’’ LTTE chief negotiator Anton Balasingham told a press conference here at the conclusion of four days of hard negotiations with the Sri Lankan government. Noting that since the political mainstream in Sri Lanka was democracy, he said LTTE would allow other political groups in the North and East.He also admitted for the first time that LTTE had recruited child soldiers during the two decades of war with the Sri Lankan forces, but said, ‘‘we do not recruit any underage persons following conventions of the United Nations.‘‘We have been releasing a large number of young persons. They have been handed over to their parents.’’ Asked if he was acknowledging that the Tigers had recruited child soldiers in the past, Balasingham said: ‘‘yes’’.It was the first public acknowledgment of the kind, although the UN and Human Rights groups have accused the LTTE of kidnapping and recruiting child soldiers.But the rebels warned the island’s judiciary not to ‘‘dig up the past’’ with legal action against them that could scuttle the peace process. They were referring to an order of the Sri Lankan court that sentenced Prabhakaran in absentia to 200 years in jail.