KIEV, Ukraine - A landmark co-operation agreement between Ukraine and the European Union is likely to be derailed Monday over the jailing of former Prime Minister Yulia Tymoshenko.

Ukraine and EU officials had long planned to use the Monday Ukraine-EU summit to commit to the deal outlining deep political and economic co-operation between Kiev and the 27-nation bloc it aspires to join.

But Brussels is likely to reject the agreement after a court handed a seven-year jail sentence to Tymoshenko, now the country's top opposition leader, on charges of abuse of office, officials and experts have said. Both the EU and the United States have strongly condemned the October verdict as politically motivated and demanded her release.

Tymoshenko was found guilty of overstepping her authorities while negotiating a natural gas import contract with Russian in 2009. She maintains her innocence and charges that President Viktor Yanukovych, her longtime foe, masterminded the legal assault against her in order to bar her from next year's elections.

Yanukovych has resisted the pressure to release her, saying prosecutors and courts have acted independently in Tymoshenko's trial. Moreover, Tymoshenko has been charged and investigated in scores of new criminal cases since her imprisonment. A court has ordered her indefinite arrest as part of new probe, even if her current jail term is overturned.

A Kiev court is now hearing an appeal of her sentence, and the next hearing is scheduled for Tuesday. Tymoshenko has been unable to attend the appeals hearings, claiming severe back and skin problems, and saying the authorities are denying her proper treatment.

Tymoshenko's jailing has presented the EU with a dilemma. Some experts believe that Brussels should not be partners with a government that throws opposition leaders in jail. Others say that snubbing Ukraine would push it back under Russia's influence as Kiev is courting Moscow for cheaper natural gas.