Susil Premajayantha, the UPFA general secretary, said that following the last night meeting of the alliance's constituent party leaders, Sirisena agreed to let Rajapaksa contest, six months after he vanquished the 69-year-old former strongman in the presidential polls.
Rajapaksa had publicly announced on Wednesday for the first time since he lost to Sirisena in the January polls that he wanted to run for parliament in the August 17 election.
Till late last night, the former Sri Lankan president's attempt to stage a political comeback and become the prime minister had suffered a setback when talks within the UPFA to let him lead the campaign in the general elections failed.
Constituent party leaders of the UPFA had met Sirisena to make a last-ditch attempt to see if Rajapaksa could be made the primeministerial candidate in the parliamentary elections.
Rajapaksa has vowed to eliminate corruption in public life though his decade-long rule was marked with corruption allegations, nepotism and disregard to rule of law.
Several top-ranking officials of Rajapaksa's administration, including his two brothers and wife, have been interrogated on misappropriation charges.
