MEXICO CITY (AP) — Mexico’s Senate on Wednesday approved a reform of the country’s electoral institute, a move that opponents say will undercut democracy but which the president contends will save money and reduce political privileges.

Lawmakers voted 72-50 in favor of the controversial overhaul of the body overseeing Mexico’s elections. Opponents immediately said they will challenge the changes in the supreme court. Protests are planned in multiple cities.

The reform still needs to be enacted by President Andrés Manuel López Obrador, but that is seen as a formality since he backs the initiative, which would reduce the size of the institute and limit its supervisory and sanctioning powers.

Some opposition lawmakers held up posters reading: “Morena wants to steal the elections,” referring to López Obrador’s ruling Morena party. Mexico has presidential elections scheduled for next year.

The legislative initiative, known as “Plan B”, was proposed by the president in December after he did not obtain enough votes in Congress for a constitutional reform that carried deeper electoral changes.

The president has repeatedly denied that the reform package could put the elections in Mexico at risk, saying the initiative seeks to cut the National Electoral Institute’s large budget and end its privileges.