§ 629. Criminal penalties

Whoever shall forcibly resist, oppose, impede, intimidate or interfere with a duly authorized representative of the Equal Employment Opportunity Commission while it is engaged in the performance of duties under this chapter shall be punished by a fine of not more than $500 or by imprisonment for not more than one year, or by both: Provided, however , That no person shall be imprisoned under this section except when there has been a prior conviction here­under.