These images show Cho Jun-hyuk (left), a conservative former one-term lawmaker, and Jung Keun-sik, a progressive honorary professor of sociology at Seoul National University, campaigning for their runs for the Seoul education superintendent on Sunday. (Yonhap)

Voters in Seoul headed to the polls on Wednesday to select the city's new education superintendent in a by-election, with a close race expected between a conservative former lawmaker and a progressive honorary Seoul National University sociology professor.

The superintendent seat of the Seoul Metropolitan Office of Education is one of five local administrative positions up for grabs in Wednesday's by-elections, with voting running from 6 a.m. to 8 p.m.

The position was vacated when left-leaning predecessor Cho Hee-yeon, who had served since 2014, received a suspended prison sentence in August for abuse of power and was stripped of his term.

Three candidates are running for the new Seoul education superintendent, but the race is expected to be a close two-way contest between Jung Keun-sik, a progressive honorary professor of sociology at SNU, and Cho Jun-hyuk, a conservative former one-term lawmaker.

A win by Cho would end a decade of progressive control of the Seoul education chief position. He has pledged comprehensive education reforms aimed at enhancing students' basic academic abilities, including restoring regular pen-and-paper exams for elementary school students.

He has also campaigned for the abolition of the city's Ordinance of Student Rights, blaming it for undermining teachers' authority. He has pledged to enact a new ordinance outlining students' duties instead.

Cho is the first unified conservative candidate for Seoul education chief since 2014, when Cho Hee-yeon won the first of his three terms as a unified progressive candidate against two conservative bloc candidates.

Jung has pledged to inherit the previous progressive superintendent's liberal policies, criticizing his rival's plan to reintroduce pen-and-paper exams for elementary students as "regressive."

He argues that activity-based assessments are more suitable for elementary students' education.

A low turnout of 20 percent is forecast for the Seoul education superintendent election, with advance voting over two days last week recording one of the lowest rates at 8.28 percent. (Yonhap)