The negative assessment of Yoon's conduct of state affairs slipped 3 percentage points to 71 per cent, according to local pollster Gallup Korea, Xinhua news agency reported.

Support for the ruling conservative People Power Party sank 2 percentage points to 27 per cent this week compared to the previous week.

The main liberal opposition Democratic Party's popularity rating decreased by 2 percentage points to 34 per cent.

The minor left-leaning Rebuilding Korea Party posted a 7 per cent support score this week, while the minor centre-right New Reform Party logged 3 per cent.

The results were based on a survey of 1,002 voters conducted from Tuesday to Thursday. It had plus and minus 3.1 percentage points in margin of error with a 95-per cent confidence level.