Mexican finance minister Jose Antonio Meade resigned Monday to run for president, with what many pundits see as the best chance to beat the current front-runner, the leftist firebrand Andres Manuel Lopez Obrador.

Meade announced he would seek the nomination of the ruling Institutional Revolutionary Party (PRI), which is desperately looking to hold onto power as President Enrique Pena Nieto winds down his six-year term amid dismal approval ratings.

Meade, an independent until now, is not a member of the PRI and still needs its nomination.

But that outsider status may be just what he and the ruling party need at a time when Mexicans are fed up with politics as usual.

With violent crime soaring, corruption festering and Latin America's second-biggest economy teetering on the brink of recession, many voters are looking for alternatives to the only two parties that have ruled modern Mexico: the PRI and its conservative rival, the National Action Party (PAN).

Meade, 48, touted his track record as minister, promising a Mexico where "families will always have food on the table, security on the streets, quality housing, health care and education."

A lawyer and economist, he earlier served as foreign and social development minister under Pena Nieto, and was energy and finance minister under Felipe Calderon of the PAN (2006-2012).

In announcing Meade's resignation, Pena Nieto -- who is barred by term limits from standing again -- praised him as "a good man, with a vocation for public service and a deep love of Mexico."

- Back-room politics -

That tacit endorsement appeared to seal what would be the PRI's first nomination of a non-party member to stand as its candidate for president.

The party changed its rules in August to allow a non-member to be nominated.

The PRI, which ruled Mexico as a one-party state from 1929 to 2000, has traditionally chosen its candidate in an opaque back-room process that ends with the president picking his own successor.

But this time Pena Nieto faced resistance to picking a close ally from within the party: the percentage of Mexicans who approve of his government is currently in the 20s to low 30s, according to recent polls.

Many Mexicans both in and outside the PRI see Meade as the best hope to defeat Lopez Obrador, a populist whose enemies revile him as fervently as his supporters back him.

Two-time presidential runner-up Lopez Obrador -- widely known by his initials, AMLO -- makes the Mexican establishment nervous with his talk of a new economic model and attacks on free trade, at a time when Mexico is in delicate negotiations with the US and Canada on a new version of the NAFTA trade agreement, a pillar of its economy.

His populist message has generated a swell of support in a country sick of constant corruption scandals and horrific violence unleashed by an all-out war on the country's multi-billion-dollar drug cartels.

But critics call Lopez Obrador a radical leftist who will steer Mexico down the same path as crisis-torn Venezuela.

With the rest of the opposition deeply divided, many political analysts have suggested Meade could bring the right mix of outsider status and broad appeal.

"Being a party outsider, he may be able to downplay discontent with the PRI. There may be people who will vote for him who wouldn't vote for a (traditional) PRI candidate," sociologist Jose Antonio Crespo told AFP.

But the Eurasia Group consultancy cautioned that Meade remains "the candidate representing continuity in an election of change."

Meade was replaced as finance minister by Jose Gonzalez Anaya, who previously headed state oil company Pemex.