Heinz-Christian Strache, leader of Austria's far-right Freedom Party and Austrian Vice Chancellor resigned Saturday afternoon, amid a crisis at the heart of Austria's right-wing coalition government.

Strache's resignation followed a leaked video in which he offered to trade lucrative government contracts for campaign donations from a supposed Russian millionaire.

In a brief statement to the press in Vienna, Strache described his actions as "dumb, irresponsible and a mistake," but also said that his political enemies conspired to get rid of him. "It was a carefully planned political assassination," Strache said.

Norbert Hofer — who nearly won the Austrian presidency in 2016, now Austria's infrastructure minister — will replace Strache as Freedom Party leader.

Austrian Chancellor Sebastian Kurz is due to speak publicly about the scandal this afternoon. Waiting for his appearance — which could include a call for a snap election — several thousand critics demonstrated on Vienna's Ballhausplatz, in front of the chancellor's office.

Several thousand people have now gathered in front of Sebastian Kurz's office, awaiting his decision on future of coalition. Austrian public broadcaster describes atmosphere as "extremely agitated" and at times "aggressive". #strachevideo

Strache's resignation comes a week ahead of crucial European Parliament elections as parties are making their final pitches to voters.

The Freedom Party had been due to join a major rally with Italian deputy prime minister Matteo Salvini in Italy.

Frans Timmermans, the socialist candidate for European Commission president immediately pounced on the scandal during campaigning today.

Look who Orban’s friends are. Strache, you will hear more about him today. And Salvini and Farage. They all admire Putin. Is that good for Hungary and for Europe? I don’t think so!

— Frans Timmermans (@TimmermansEU) May 18, 2019