President Moon Jae-in's approval rating dropped slightly last week from a week earlier, a poll showed Monday, apparently due to a dispute over the extended detention of the ousted former leader.

In a survey conducted by Realmeter Monday through Friday, 67.8 percent of the respondents said they approved of the way the president managed state affairs, down 0.7 percentage point from a week earlier.

The weekly survey involved 2,557 adults throughout the country. It had a margin of error of 1.9 percentage points, with a confidence level of 95 percent.

The slight decrease was partly attributed to the extension in the arrest of former President Park Geun-hye, who called it a political retribution. The former leader had been detained since March, when she was removed from the office by a Constitutional Court decision. She currently faces a criminal trial over corruption allegations.

"Former President Park's remarks over a political retribution appears to have had some impact as Moon's approval rating slightly dropped following two consecutive weeks of increase," the local pollster said in a press release.

Of all respondents, 27 percent said they did not approve of the way the president managed state affairs, up 1.2 percentage points from a week earlier.

The ruling Democratic Party too suffered a slight drop in its approval rating, which came to 50.1 percent, down 0.5 percentage point over the cited period.

The main opposition Liberty Korea Party's approval rating slipped 0.8 percentage point to 18.1 percent. The former ruling party told the former president to voluntarily sever her ties with the party.

The liberal People's Party and the splinter conservative Bareun Party saw their approval ratings go up by 1.3 percentage points and 0.3 percentage point, respectively, to 6.2 percent and 5.8 percent.

The progressive Justice Party scored 4.9 percent, up 0.1 percentage point. (Yonhap)