strike for (something)
1. To engage in a cessation of work as a part of a job action demanding some desired outcome or result. Employees have been striking for more flexible parental leave. Teachers across the state are striking for better working conditions.
2. To engage in such a cessation of work for a particular length of time. We've been striking for weeks, and the company still hasn't budged an inch on this issue.
strike for something
to conduct a work stoppage in order to gain something. The workers were striking for longer vacations. We are striking for higher pay.