Mexico's opposition seeks to block judicial reform in the Senate

MEXICO CITY (Reuters) - Mexico's opposition senators are uniting around the possibility of blocking controversial judicial reforms pushed by President Andres Manuel Lopez Obrador, which will go to a vote next week, suggesting its passage might not be as easy as first thought.

The ruling party Morena and its allies are currently one vote short of the two-thirds majority in the Senate needed to pass the reform, which would overhaul Mexico's judiciary by electing judges through popular vote.

Most analysts still expect the ruling bloc to find that Senate vote, or for absentees to mean it is not needed, but the opposition - despite being weakened by infighting and a drop in public support - is resisting.

On Friday, president of the opposition PRI party Alejandro Moreno said all 15 senators from his party would vote against the reform in a radio interview with Grupo Formula.

That followed a video posted on Thursday on X by Daniel Barreda, senator for the Citizens' Movement (MC) in which he said he had decided to vote against the reform, flanked by the other four senators of the party.

Opposition lawmakers have also denounced attempts by the ruling bloc to intimidate or buy senators' support, allegations Morena has denied.

The reform passed the lower house this week amid street protests that forced the vote to be moved to a sports complex.

Morena and its allies have secured 85 senate seats, two of which were gained via negotiations with senators who changed their allegiance after the June election.

As two thirds of the Senate's 128 seats mathematically equates to 85.3, debate has risen over whether the ruling bloc needs 85 or 86 votes. Adan Augusto Lopez, the leader of Morena in the Senate, has suggested 85 may be enough though the opposition and many legal experts say it is 86. That means a challenge is likely if the final vote falls exactly 85 to 43.

The reform has generated concern among investors and the U.S. ambassador to Mexico, who worry that it would weaken a crucial check and balance of the executive branch and damage the business climate in Latin America's second-largest economy.

(Reporting by Stephen Eisenhammer; additional reporting by Diego Ore and Ana Isabel Martinez; editing by Sam Holmes)