N.Y. General Obligations Law § 5-301: Certain employment contracts void

§ 5-301. Certain employment contracts void. Every undertaking or

promise, whether written or oral, express or implied, constituting or

contained, in any contract or agreement of hiring or employment between

any individual, firm, company, association or corporation and any

employee or prospective employee of the same, whereby (a) any employee

or prospective employee undertakes or promises to join, become or remain

a member of a company union; or (b) either party to such contract or

agreement undertakes or promises not to join, become, or remain a member

of any labor organization or any organization of employers; or (c)

either party to such contract or agreement undertakes or promises that

he will withdraw from the employment relation in the event that he

joins, becomes or remains a member of any labor organization or of any

organization of employers, is hereby declared to be contrary to public

policy and wholly void and shall not afford any basis for the granting

of legal or equitable relief by any court against a party to such

undertaking or promise, or against any other persons who may advise,

urge or induce, without fraud, violence, or threat thereof, either party

thereto to act in disregard of such undertaking or promise.