By Marco Aquino and Mitra Taj

LIMA (Reuters) - The biggest political protests in Peru's capital in more than a decade have pressured President Ollanta Humala to clean up government and share the benefits of the country's decade-long economic boom.

Many of the protesters were left-leaning and middle-class youth who voted for Humala two years ago, but now they say he and other political leaders are dangerously out of touch.

A former military officer and one-time nationalist radical, Humala has pledged to ensure more Peruvians benefit from growth rates of around 6 percent a year, record reserves and solid fiscal surpluses.

Humala has largely pleased investors by continuing free-market policies, but detractors say he has not made much progress on the "great transformation" he once promised.

With a quarter of Peruvians living in poverty, and crime and corruption still widespread, Humala's approval ratings have slumped.

The street protests peaked with a rally of around 8,000 at the end of July. They were small compared to other protest movements in Latin America, but the biggest in Lima since 2000, when demonstrators took to the streets against President Alberto Fujimori. He was forced from power that same year and is in prison for corruption and human rights violations.

The recent protests spilled over from social media and into the streets last month after lawmakers in Humala's party were caught on tape negotiating controversial appointments for judges and a human rights ombudsman in an under-the-table deal with other major parties.

While recent demonstrations were directed against all of Peru's political class, they highlighted Humala's political isolation as he struggles to push through education, health, policing and civil service reforms. The government is clearly concerned.

"If the political class in power does not change, this could become massive and the government is aware of that," a senior figure inside the Humala administration told Reuters.

The source, who declined to be named, said the prime minister has been meeting with youth leaders to calm the "crisis of representation."

"We are going to act very carefully so that the work of the government and of Congress is in tune with them," he said.


Humala had a 65 percent approval rating shortly after taking office two years ago, but a recent Ipsos poll showed it had fallen to 33 percent. He had to shuffle his Cabinet twice after anti-mining protests in rural areas, although he is more popular than two former presidents at a similar time in office.

Ex-president Alan Garcia has tried to ride the recent discontent to boost his own flagging popularity as he faces investigations for alleged wrongdoing in handing out pardons to drug dealers during his 2006 to 2011 government.

Garcia's APRA party was not part of the congressional bargain that triggered the protests. He says the appointments scandal shows the government is trying to usurp democratic institutions.

A pro-business conservative, Garcia is widely expected to seek a third term in office in 2016 elections.

Humala can not seek a second consecutive term, but his charismatic wife, Nadine Heredia, is widely believed to have presidential ambitions. Some expect her to run as early as 2016, despite her denials.

Faced with the growing street protests and the prospect of more trouble, Congress quickly annulled its institutional appointments.

"The lesson that has been learned, at least by the political elite in Lima, is that you can't just get away with anything anymore," political scientist Steve Levitsky said.

Echoing similar movements in Brazil, Chile and Spain, Peru's demonstrators have focused on corruption and back-room politics.

"Before protests used to be divided into specific things," said Milagros Olivera, a 19-year-old university student at a march downtown last month. "But now we are showing our broad rejection of the government."

The demonstrations featured labor union members, a soap opera actor, gay rights activists in rat costumes, and a giant pan flute band that dedicated songs to a Peruvian socialist hero. They ended in clashes and police firing tear gas into the crowds.

Peru's middle-class has largely shied away from political activism since the war between the state and the Shining Path rebel group in the 1980s and 1990s that claimed some 70,000 lives.

"The Shining Path experience still weighs very heavily on Peruvian politics," said Levitsky. "Anything that smacks of protests ... or violence or police crackdowns really raises the hair on the back of people's necks."

But that could be changing as younger people who came of age after the worst of the conflict become politically aware.

"What's new here is us - young people like me who have never protested before," said 21-year-old university student Julio Salazar.

Analysts say the protests and a broader rejection of the traditional political parties could encourage outsiders to make bids for office.

Political parties in Peru tend to be weak and centered around the personalities of current and former presidents, and many feel politicians are more interested in posturing for 2016 presidential elections than solving problems.

Marco Sifuentes, a 34-year-old journalist who was active in the recent rallies, said most protesters were under 40.

"They're very connected to global events and more likely to associate protests with those in other parts of the world than with the Shining Path," he said. "This has opened a door."

(Additional reporting by Omar Mariluz; Editing by Kieran Murray and Stacey Joyce)

[A protester wearing a Guy Fawkes mask attends a demonstration against President Ollanta Humala's government on Peru's Independence Day in Lima, July 28, 2013. REUTERS/Mariana Bazo]