MEXICO CITY, Jan 28 — Mexican President Andres Manuel Lopez Obrador's ruling party plunged into a divisive leadership struggle yesterday when party chief Yeidckol Polevnsky refused to stand down after being voted out by opponents.

Lopez Obrador's National Regeneration Movement (Morena) party reshaped Mexico's political landscape with a convincing victory in the 2018 elections, winning majorities with its allies in both houses of Congress.

But Morena, formally registered in 2014, has struggled to pick a new leader amid infighting between different wings of the party.

Divisions in Morena at a time when the economy is stagnant and homicides are at record levels risk eroding the party's grip on Congress with a new lower house due to be elected next year.

Protracted infighting within in the Mexican left, which has long been highly factional, could also be an unwelcome distraction from Lopez Obrador's plans for a so-called "recall” referendum on his leadership in the spring of 2022.

On Sunday senior Morena congressman Alfonso Ramirez Cuellar was elected as temporary leader by a party congress of more than 1,000 representatives until a new leadership election is held in a few months' time.

But Polevnsky, who had led the party since Lopez Obrador stepped down before the 2018 general election, on Monday refused to recognise Sunday's vote, saying it broke party rules.

"We will continue to lead in strict adherence to (party) legality and our statute,” she said on a video on Twitter.

Some sections of the party backed Polevnsky while others welcomed Ramirez Cuellar's appointment.

Lopez Obrador declined to be publicly drawn into the dispute.

"It should be resolved democratically,” Lopez Obrador said during his daily morning press conference. "Don't get me involved in the question of party politics.” — Reuters