The lower house of Mexico's Congress gave final approval to a bill authorizing the holding of referendums on certain issues "of national significance."
Already ratified by the Senate, the measure passed by a vote of 362-57 with four abstentions.
The initiative to convene a referendum can originate with the president, one-third of the members of either house of Congress or 2 percent of registered voters.
A proposal from the chief executive or legislators will require majorities of both the Senate and lower house for a plebiscite to take place, while the Supreme Court will decide on citizen initiatives.
The legislation bars referendums on proposals that would restrict any rights enshrined in Mexico's constitution or alter the Aztec nation's institutional identity as a democratic, federal republic.
Also off-limits are matters relating to taxes and spending, national security and the armed forces.
"The Federal Law on Popular Referendums strengthens our democracy and allows citizen intervention to implement their opinion, by way of law," congressman Abel Octavio Salgado, a member of the governing Institutional Revolutionary Party, or PRI, said.
Speaking for the Citizens' Movement, Alfonso Durazo, said the law "has so many limitations that it will be difficult for us to use it to advance a bill based on popular initiative."
The center-left PRD party is pushing for a referendum on the PRI administration's energy reform, which is opposed by the Mexican left and even by some in the ruling party.
The overhaul ends state-owned Pemex's monopoly on oil and gas production, in place since the company was created in 1938 as part of then-President Lazaro Cardenas nationalization of the energy industry. EFE