Chilean lawmakers voted on Thursday to reject a move to impeach President Sebastian Pinera over allegations that he had failed to prevent human rights abuses over weeks of protests.

Lawmakers tossed the motion out on grounds that it did not meet the Constitutional threshold for ousting a sitting president.

Pinera has been accused over allegations he failed to safeguard human rights during weeks of rioting, a political test that he is likely to survive but may still batter his teetering presidency. 

Small-scale protests that began in October over a hike in metro fares quickly spiraled out of control, leaving 26 dead, billions of dollars in damage and widespread allegations of abuses by security forces. 

Pinera has borne the brunt of the blame. His approval rating at the end of November plunged to just 10 percent, the lowest for a president since 1990.

The most prominent grievances, from overhauling Chile's creaking pension system to slashing the cost of public services, date back to decisions made well before Pinera's time.

Lawmakers from several opposition parties behind the impeachment bid say Pinera, who early in the crisis declared Chile "at war with a powerful enemy," failed to act quickly enough to stamp out police abuses. 

That argument led Chile's Senate late on Wednesday to censure Pinera's former interior minister and cousin Andres Chadwick, stripping him of his right to hold public office for five years. 

Pinera's legal team contends there is no link between his actions and any constitutional wrongdoing. 

Several international rights groups have condemned police abuses. Pinera has promised deep reforms to police protocols. 

A long or raucous debate on Thursday in the Chamber of Deputies could further dent Pinera's image. If the chamber approves the impeachment motion, the Senate would then be required to hear the allegations in its next session.

Impeachment, however unlikely, would create more political chaos, said University of Chile public law professor Francisco Soto.

"The Constitution establishes a high bar for impeachment because it would put the country in a very complex situation," he said.

Pinera is the first president to face impeachment in Chile in more than 60 years, when lawmakers tried but failed to oust General Carlos Ibanez del Campo.