Vice President of the European People's Party Mario David said Tymoshenko must be freed for the agreement to be finalized at a December summit in Kiev, RIA Novosti reported Friday.
Tymoshenko's trial and conviction have jeopardized the creation of a free trade zone with the EU.
"This is not only about decriminalization [the statutes under which Tymoshenko was convicted], but also changing the approach," David said.
David added Tymoshenko should be allowed to participate in elections after her release.
Ukraine is holding its next parliamentary election in the fall of 2012.