The complexity of political life has witnessed the rise of many groups referred to as pressure groups, interest group or influence groups. They are voluntary organisations, with a particular interest. They do not participate in contest for power in elections. Though they help some parties for their interest, but they do not fight elections.

They try to build public opinion in their favour and do not seek to capture power but only to influence decisions. As Arthur Bentley remarks, “Public policy is the result of interplay of group forces.”

Pressure groups are a term applied to those interest groups which use different pressure tactics including extra-constitutional methods to pursue their goals.