Poll finds unprecedented uncertainty among French voters before presidential election

Candidates for the 2017 presidential election (LtoR) Francois Fillon, former French Prime Minister, member of the Republicans and candidate of the French centre-right, Emmanuel Macron, head of the political movement En Marche !, or Onwards !, Jean-Luc Melenchon of the French far left Parti de Gauche, Marine Le Pen, French National Front (FN) political party leader and Benoit Hamon of the French Socialist party (PS) pose before a debate organised by French private TV channel TF1 in Aubervilliers, outside Paris, France, March 20, 2017. REUTERS/Patrick Kovarik/Pool

PARIS (Reuters) - Nearly half of all French voters have yet to decide who they want to be president with only a month to go until the election, an opinion poll showed on Friday.

Amid the unprecedented level of voter uncertainty, a senior Socialist minister revealed he was abandoning his party's candidate and backing favourite Emmanuel Macron in a bid to keep far-right leader Marine Le Pen from power.