The chief of the Korea Enterprises Federation has written letters to National Assembly lawmakers, voicing concern over the so-called “yellow envelope bill” that passed a session of the National Assembly’s Legislative and Judiciary Committee on Friday.

According to the federation, Sohn Kyung-shik, chairman of KEF, sent letters to all 298 lawmakers at the National Assembly about the contentious bill, which would change the law on labor unions to significantly restrict companies from suing striking workers.

Sohn, who also serves as chairman of CJ Group, stated in the letter that companies are greatly worried about the bill, which may influence corporate management decisions as well as that of parent companies as part of labor actions.

Sohn added that sectors such as automobiles, shipbuilding and construction which involve a multi-level labor system would see an endless stream of labor disputes should the amendment take effect.

The bill to amend Articles 2 and 3 of the Trade Union and Labor Relations Adjustment Act classifies as an employer any entity that “substantially and specifically controls” working conditions, meaning subcontracted workers could negotiate directly with parent companies.