The main role of pressure groups is to influence the government and other decision-making bodies on behalf of a particular interest or cause. This influence may come in the form of lobbying, campaigning, protests, and other forms of activism. The ultimate goal of pressure groups is to bring about changes in laws, policies, or practices that they believe will benefit their members or advance their cause. However, it's important to note that while some pressure groups may resort to unethical or illegal means to achieve their objectives, the majority rely on legitimate and peaceful methods to advance their goals.