South Korean President Lee Jae-myung's approval rating fell 2.5 percentage points from a week earlier to 67.4 percent last week, a weekly poll showed Monday.

The negative assessment of Lee's conduct of state affairs increased 3.4 percentage points to 31.6 percent, according to computer-assisted telephone interviewing (CATI) by local pollster Flower Research.

The ruling liberal Democratic Party's support retreated 4.8 percentage points to 51.4 percent, while the conservative opposition People Power Party's approval score gained 2.0 percentage points to 27.4 percent.

Support rate for the minor left-leaning Rebuilding Korea Party and the minor rightist New Reform Party logged 2.2 percent and 3.6 percent each last week.

The pollster's separate survey of the automated response system (ARS) showed that Lee's approval rating declined 3.5 percentage points to 61.0 percent last week compared to the previous week.

Both the CATI and the ARS surveyed 1,002 voters from Friday to Saturday. They had plus and minus 3.1 percentage points in margin of error with a confidence level of 95 percent.