Volte-face (/vɒltˈfɑːs/ or /voʊltˈfɑːs/) is a total change of position, as in policy or opinion; an about-face.
The expression comes from the French language.
In the context of politics a volte-face is, in modern English, often referred to as a U-turn (in the UK and US) or a flip-flop or about-face (US).