Spurned by president, Peru leftists protest mining
* Nine-day march in Peru against major projects
* Leftists abandoning President Humala
LIMA Feb 9 (Reuters) - Left-wing activists and provincial politicians frustrated by President Ollanta Humala's move to the political center marched into Lima on Thursday to protest billions of dollars in government-backed mining projects proposed by foreign firms.
At least 1,000 people participating in a nine-day walk across the countryside arrived in the capital to pressure the government to withdraw support for the projects, which include U.S.-based Newmont Mining's $4.8 billion Conga mine and two projects by Southern Copper worth $1.8 billion.
The government wants to push ahead with $50 billion in mining projects, saying they are crucial to stoke expansion in one of Latin America's fastest-growing economies.
But the protesters say mining pollutes, soaks up scarce water supplies, and has historically failed to bring enough direct local benefits to impoverished rural towns in Peru.
They carried signs saying "there's gold, there's copper and the people are still poor," a phrase that rhymes in Spanish.
Peru is the world's second-largest copper, silver and zinc producer and Latin America's top gold producer. Mining fuels the economy by accounting for 60 percent of Peru's exports.
"We have to make a choice between mining and water," said Marco Arana, a former Roman Catholic priest and leader of the left-wing party Tierra y Libertad. He supported Humala in last year's presidential election but is now a fierce critic.
Humala, a former military officer shed his hard-line leftist past and reinvented himself as a moderate to win the presidency last June. He has embraced mainstream economic policies since taking office and forged strong ties to the business community that represents Peru's political right.
His swift political evolution has disappointed traditional allies and left his party with a tenuous working majority in Congress because of high-profile defections from his coalition.
ENVIRONMENTAL IMPACT QUESTIONED
Gregorio Santos, the top elected official in the region of Cajamarca, has led opposition to the Conga project and banded together with political leaders in Peru's 25 regions to pressure Humala.
"All regional leaders should unite to make the government address the issue of pollution and overuse of water by miners," he said.
Newmont says it has conducted an exhaustive environmental impact study for its mine, which has been cleared by the government but now faces stiff opposition.
It says the project would guarantee year-round water supplies, in part by building reservoirs that would replace a string of alpine lakes.
The Conga dispute is one of 200 environmental conflicts nationwide that Humala and Prime Minister Oscar Valdes are struggling to manage.
"I would like it if the march weren't political but rather technical - so that the leaders really make it clear what they see is the water problem," Valdes said.
Valdes has put the Conga project's disputed environmental impact study in the hands of international experts in hopes protesters will accept the verdict of what he says will be an objective audit.
Fernando Rospigliosi, a prominent columnist, said the march appeared to be more about ideology than water, especially because record rains have swollen rivers in Peru this month and caused floods.
"Heavy rains prove Arana and the anti-miners wrong: there's not a lack of water. There's a lack of infrastructure to dam and channel water," he said.