Key officials of the ruling People Power Party (PPP) have offered to resign over the party's recent by-election defeat.

In a notice issued Saturday, PPP chief spokesperson Yoo Sang-bum said that all appointed staff members including secretary-general Lee Chul-gyu and vice chief of strategy and planning Park Sung-min will step down for the stability and further advancement of the party.

This comes three days after a crushing defeat in Wednesday's by-election for ward chief of Seoul's Gangseo District in which the main opposition Democratic Party candidate won over 56 percent of the vote versus the PPP's 39 percent.

The election was viewed as a test bed of voter sentiment ahead of next year's parliamentary election.

One PPP official told KBS that as the party lost the latest vote by a double digit margin, echoing the defeat of the 2020 general elections, taking responsibility for the defeat on a party level was inevitable.