Owing to the power cut in the area, factories are being forced to ...... men

In this context, "lay off" means to terminate the employment of workers due to a lack of work or economic reasons. The sentence suggests that because of the power cut affecting production in the factories, they are being compelled to reduce their workforce by terminating employees. Therefore, "lay off" is the correct choice to complete the sentence, accurately conveying the action of forced unemployment due to the power cut.