Mexico's presidential front-runner Enrique Pena Nieto has extended his big lead in the run-up to the July 1 election following a sharp drop in support for the ruling party candidate, an opinion poll showed on Monday. The voter survey by polling firm Buendia & Laredo for newspaper El Universal showed backing for Pena Nieto, candidate of the opposition Institutional Revolutionary Party (PRI), at 41.6 percent, down from 42.5 percent in a poll published on March 26. However, due to a decline in the fortunes of Josefina Vazquez Mota, candidate of President Felipe Calderon's conservative National Action Party (PAN), Pena Nieto...
