Political leaders ratcheted up their battle over ideology on Wednesday as the nation remembered fallen patriots including soldiers killed during the Korean War.

President Lee Myung-bak used his address for the 57th Memorial Day to denounce “those who try to destroy the constitutional order.”

“The people of the Republic of Korea will never tolerate anyone who attempts to negate liberal democracy,” Lee said in the speech at the National Cemetery.

The ruling Saenuri Party is pushing to expel some lawmakers in the main opposition Democratic United Party and minority Unified Progressive Party.

They are accused of past pro-North Korea activities while opposing previous military-backed governments and promoting reconciliation between the two Koreas.

UPP members are also facing disciplinary measures in connection with a fraudulent in-house vote and violence during a party meeting last month.

The Saenuri Party’s presidential frontrunner Park Geun-hye also issued a veiled warning against the alleged North Korea sympathizers.

She said on Twitter that the nation should “defend this country and freedom and hand them unscathed to our descendents.”

Opposition politicians stepped up their criticism of the ruling camp for communist-bashing in pursuit of political gain in the lead up to the December presidential election.

“It is an intolerable crime if a party seeks to win the presidential election by means of McMcCarthyist fanaticism,” Rep. Lee Hae-chan, a candidate for party chairman of the DUP, said in a radio interview.

DUP chief Rep. Park Jie-won also demanded President Lee and Park cease accusations about political ideology.

On the previous day Saenuri chief Rep. Hwang Woo-yea pledged to expel DUP lawmaker Lim Su-kyung, who had called North Korean defectors “traitors,” as well as Lee Seog-gi and Kim Jae-yeon of the scandal-ridden UPP.

“Lawmakers who fail to respect basic human rights and democratic order may have to be reevaluated in their qualifications,” Hwang said.

By Bae Hyun-jung (tellme@heraldcorp.com)