He also opposed the Prime Minister's move to give blanket amnesty to all human rights abusers of the decade-long insurgency adding that the guilty must be punished.
He, however, expressed readiness to discuss the terms and conditions of the proposed Truth and Reconciliation Commission for working out transitional justice mechanism.
"We want to establish lasting peace, stability and consolidate democracy so that we can make the country prosperous by utilising the valuable gifts of the nature," Koirala said addressing the final protest meeting of the three weeks long protest programme jointly organised by nine political parties in a bid to remove Baburam Bhattarai's government.
President of CPN-UML Jhalanath Khanal said "the Maoists will be eliminated from the country if they tried to impose dictatorship and totalitarian regime."
He underlined the need to form a national unity government by dislodging the caretaker government led by Bhattarai "in order to hold fresh election at the earliest that would promulgate the constitution to consolidate the achievements of the Peoples Movement of 2006".
Nepal plunged into political crisis after a 601-member interim legislature elected to draft a post-war Constitution was dissolved by Maoist Prime Minister Baburam Bhattarai in May last year.
Elections promised for November were also shelved amid serious differences among the main political parties over who should lead a national unity government.
Pointing to the ongoing political and economic crisis facing the country, Khanal said that there is a need to forge cooperation and collaboration among all the political forces to rescue the country from the ongoing deadlock.
He also slammed the Maoist-led government "for rampant corruption, increasing price hikes, poor law and order situation and the state of anarchy."
Earlier, thousands of opposition cadres moved around the major parts of the city shouting anti-government slogans.