Poland has refused to back an EU package deal that would release 18 billion euros in aid for Ukraine, Politico reported, citing four unnamed EU diplomats.

The refusal also blocks two unrelated decisions on Hungary due to hesitation regarding a separate minimum corporate tax plan.

“There’s a lot of frustration with Poland jeopardizing Ukraine aid by blocking the minimum tax,” one of the diplomats told Politico, calling the move “another hostage-taking situation.”

Poland’s blocking of the minimum corporate tax rate is hindering aid to Ukraine because if one of the four points is vetoed, all issues will not pass, according to Politico.

The EU member states planned to adopt the package deal on Dec. 14, but Poland requested for a deadline extension, the sources said.

Polish Prime Minister Mateusz Morawiecki is now expected to raise the issue at a meeting of EU leaders in Brussels on Dec. 15, although it is not formally on the agenda, according to the diplomats.

The European Parliament finally approved an 18 billion euro macro-financial aid package to Ukraine on Dec. 14, after striking a deal with Hungary to drop its veto.

Budapest had been blocking Ukraine's 18 billion euro support package to pressure Brussels into releasing EU funds to Hungary, frozen over its democratic backsliding, Politico, which cited four EU officials and diplomats who saw the move as a "blackmail tactic."

The parliament employed a so-called "urgent procedure" to allow 26 member states to act as the loan guarantors for Ukraine, relieving Hungary from the procedure in exchange for its approval.

The 18 billion euro support package aims to assist Ukraine with paying for essential public services, maintaining macroeconomic stability, and restoring critical infrastructure destroyed by Russian attacks.