Hungary's leader Viktor Orban sent sparks flying at the European Parliament on Tuesday as he told the EU to change tack or face "defeat" in Ukraine, and promised to pop the champagne if Donald Trump wins back the White House.

As Russian President Vladimir Putin's closest ally within the European Union, Orban's nationalist government is at loggerheads with its partners on a host of issues — from stalling aid for Kyiv, to enacting a host of laws the bloc sees as democratic backsliding.

Orban is in Strasbourg to present the "priorities" of Hungary's norm-defying EU presidency, in a Wednesday debate attended by Commission chief Ursula von der Leyen — and set to feature stormy exchanges with lawmakers bent on calling him out.