LIMA, June 16 (Reuters) - Peruvian President Ollanta Humala's approval rating fell in June for the fourth straight month to nearly the lowest level of his term, due in part to his refusal to pardon jailed former President Alberto Fujimori, according to a poll released on Sunday.
The popularity of Humala, who has been in office nearly two years, slipped to 41 percent in June from 46 percent in May, pollster Ipsos said.
His approval rating was also hurt by verbal sparring with former President Alan Garcia, who has said Humala is working to ensure his wife, first lady Nadine Heredia, can run for president in 2016, according to the Ipsos study published by the newspaper El Comercio.
Humala's charismatic wife is widely seen as a potential candidate, but current election rules would prohibit her from running to lead one of Latin America's fastest-growing economies.
According to the poll, 48 percent of respondents disagreed with Humala's decision to reject a humanitarian pardon for Fujimori. The 74-year-old former president is serving a 25-year sentence for human rights crimes and corruption during his term in the 1990s.
Another 48 percent approved of Humala's decision, according to the survey. Humala said Fujimori did not deserve a humanitarian pardon because he was not suffering from a terminal illness.
The poll said only 24 percent of respondents think Heredia should be allowed to run for office, which would require changes in election laws.
Heredia, considered by some as the "co-president," has denied she plans to run.
The Ipsos Apoyo poll of 1,226 people has a margin of error of 2.7 percentage points. (Reporting By Patricia Velez; Editing by Stacey Joyce)