Tens of thousands of people have protested in the centre of Mexico City against President Enrique Pena Nieto's planned overhaul of the energy sector. Opposition leader Andres Lopez Obrador told the crowd to surround the Congress this week. Mr Pena Nieto says the plan to allow private investment in the oil and gas sector is needed to boost the economy. His approval ratings have slumped to their lowest since he took office a year ago.