Mexican lawmakers on Wednesday approved a controversial overhaul of the body overseeing the country's elections, a move critics warn will weaken democracy ahead of a presidential vote next year.
President Andres Manuel Lopez Obrador argues the reorganization will save $150 million a year and reduce the influence of economic interests in politics.
But opposition lawmakers and civil society groups have said they will challenge the changes at the Supreme Court, arguing they are unconstitutional. Protests are planned in multiple cities on Sunday.
The Senate approved the reform, which still needs to be signed into law by Lopez Obrador, 72 to 50.
The changes will cut the budget of the National Electoral Institute (INE), cull staff and close offices.
The INE has played an important role in the shift to multi-party democracy since Mexico left federal one-party rule in 2000. Critics fear some of that progress is being lost, in a pattern of eroding electoral confidence also seen in the United States and Brazil.
Lopez Obrador has repeatedly attacked the electoral agency, saying voter fraud robbed him of victory in the 2006 presidential election.
The head of the INE, Lorenzo Cordova, has called the changes a "democratic setback" that put at risk "certain, trustworthy and transparent" elections. Proposed "brutal cuts" in personnel would hinder the installation of polling stations and vote counting, Cordova said.
The changes, dubbed "Plan B," follow a more ambitious constitutional overhaul last year that fell short of the needed two-thirds majority. That bill had sought to convert the INE into a smaller body of elected officials.
Mexico will hold two state elections in June and general elections next year, including votes for president and elected officials in 30 states.
(Reporting by Adriana Barrera and Diego Ore; Writing by Carolina Pulice; Editing by Stephen Eisenhammer, Sandra Maler and William Mallard)