The Czech Republic's Former Deputy Prime Minister breaks off addressing a meeting of dentists to deliver a hard slap to the back of Health Minister David Rath's head.
Mr Rath takes some steps away from the stage before returning to confront Mr Macek and call him a "coward".
Mr Macek hits Mr Rath again.
The two men start punching each other...
... and nearly push each other off the stage.
Mr Macek said he slapped Mr Rath because of comments he had made about his wife. The incident, on the eve of polls, has shattered the normally placid image of Czech politics.