The main opposition Democratic United Party vowed Friday to seek an “all-out renegotiation” of South Korea‘s free trade agreement with the United States, after the party gains a parliamentary majority through next month’s general elections.

The trade pact went into effect Thursday, nearly five years after it was first signed in 2007.

The landmark deal has been one of the most contentious political issues in South Korea, with the government saying it will boost exports, create jobs and further strengthen the traditional alliance with Washington, and the opposition claiming it favors the U.S.

“The DUP opposes the Korea-U.S. FTA that runs against the livelihoods of ordinary people and national interests,” DUP leader Han Myeong-sook said during a meeting of party leaders. “We will lead the party to a victory in the general elections and push for an all-out renegotiation.”

Han claimed the pact was “born out of humiliating negotiations” and railroaded through parliament, accusing the administration of President Lee Myung-bak of throwing “a party for the 1 percent rich while ignoring demands from the people.”

“Behind the smiles of President Obama are applauses and cheers from the people, but behind the smiles of President Lee are deplorations of the people, moanings of farmers and fishermen, and sighs of small and medium-sized firms and petty merchants,” Han said. (Yonhap News)