Mexico’s ruling party Morena approved four external polling companies that will conduct surveys to determine who will be their candidate for the 2024 presidential elections.

The four companies selected via lottery had been proposed by presidential candidates Claudia Sheinbaum, Marcelo Ebrard, Manuel Velasco and Adan Augusto Lopez. Ebrard’s firm was included after another candidate — former senate majority leader Ricardo Monreal — withdrew his proposal, Morena’s national head Mario Delgado said, citing a previously established order of priority.

Tensions within President Andrés Manuel López Obrador’s party rose Wednesday when Ebrard, a former foreign minister, accused Morena’s leadership of favoring his main rival Sheinbaum, the former Mexico City mayor. The selection of the polling firm proposed by Ebrard is expected to ease frictions surrounding the nomination process.

“We already have the four firms that will join us in the survey,” Delgado told reporters late Friday, according to a transcript. “They passed the test of the survey committee.”

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In separate remarks Saturday, Delgado said the candidates whose suggested polling firms had been selected would not have an advantage, given they will be accompanied by representatives of the other hopefuls when carrying out the surveys. A registration phase begins Monday for 350 people from each candidate to participate.

The firms will sign confidentiality agreements and their names won’t be released until the nominee is chosen, on Sept. 6.

López Obrador, who’s not eligible to run for reelection in June, has vowed not to interfere in the candidate’s selection. Whoever is chosen will be in a strong position to become Mexico’s next president, thanks to Lopez Obrador’s high popularity.

--With assistance from Andreina Itriago Acosta.

(Adds Delgado’s Saturday comments in fifth pararaph)