Nandana Gunathilake, a politburo member of the Marxist-nationalist party said he sent in his resignations from the high party positions on February 7, but did not go public till today.
"I thought there was a chance to reform the leadership... but it was not possible and after Mr. Amarasinghe made a statement to a newspaper saying that I have left the party, I decided to go public," Gunathilake told Sri FM radio.
Although he quit his positions within the JVP, he remains the president of the ruling United People's Freedom Alliance (UPFA), the coalition that was formed in January 2004 for the Sri Lanka Freedom Party (SLFP) and the JVP to unite and contest the parliamentary elections.
President Mahinda Rajapakse also contested the November presidential election as a candidate of the UPFA.
Gunathilake said he had wanted the JVP to take cabinet portfolios and work to strengthen the Rajapakse administration they had helped during the presidential election campaign.
"I said we should joi