In an opening speech yesterday Mexican presidential frontrunner Enrique Pena Nieto vowed to subdue the violence engulfing his country as the campaign for the July 1 election kicked off with the ruling conservatives struggling to hold onto power.

Pena Nieto, of the opposition Institutional Revolutionary Party, is the hot favourite to succeed Felipe Calderon, whose time in office has been dominated by the government's struggle to bring brutal drug cartels to heel.

Calderon's conservative National Action Party has also been criticised for its failure to create jobs.