Mexico’s Senate has advanced a controversial measure that would overhaul the country’s energy sector. Mexican President Enrique Peña Nieto wants to open the state-controlled oil company to investment from foreign multinationals after 75 years of nationalization. Jesus Zambrano of the leftist Party of the Democratic Revolution said that if given final approval, the measure should go before a national referendum.

Jesus Zambrano: “We warn all private, national and, above all, transnational businesses and companies that want to come and invest in Mexico and petroleum, in order to expropriate Mexican petroleum, to think again. The most probable outcome is that within a year and a half, a recall referendum will reject this change.”

The energy measure now goes to Mexico’s lower house for final approval.