Sex discrimination: is treating someone less favourably because of their sex.
Legislation has developed to protect men (and women) from different types of sex discrimination such as direct discrimination; harassment and indirect discrimination (which is where a policy is applied equally to everyone but particularly disadvantages men).
For example: Despite paying more taxes, men in the UK receive proportionally fewer benefits from the state in areas such as education, services, benefits and employment. For every man working in local government there are two women. The significant majority of Britan’s long term unemployed are men.
Of course gender bias concepts such as Equal Spend or Equal Pay become more complicated when considered in the context of the still statistically significant trend of partnerships forged between men and women, not to mention the sacrifices they will make for their children.