You can classify pressure groups by two ways; Core Aims and Strategy or Status. 

If you classify pressure groups by core aims, then you get sectional, a.k.a interest, groups and cause, a.k.a promotional, groups.  

Sectional Groups:

Want to represent common interest

Closed membership-only those in the industry, Teacher’s Union NASUWT who are limited to only teachers

Represent the majority of it’s members 

Members have a direct link to the interest of the group

Eg, TUC who protect wages and working conditions, British Medical Association-BMA who represent the interests of doctors and makes sure their rights are protected, Farmers Union

Cause Groups:

Seek to advance a certain cause or set of ideas that may not have a direct benefit to the members. Eg, RSPCA who try to protect the rights and well-being of animals, that may not exactly have total benefit to the members.

Open membership, anyone who shares the desire for that cause and shares the ideas can join. 

They can be quite short-lived when they have reached their goal. For example, the Snowdrop campaign to ban handguns that was combated after the 1997 Firearms legislation. 

They often have limited funds, and access to the government, as they can have too radical ideas. For example, the Campaign for Nuclear Disarmament, CND, will not gain much access to the government due to the controversy surrounding nuclear weapons. 

For Cause Groups, you can also classify them into three different sub-sections. These sub-sections being; Sectional Cause, Attitude Cause and Political Cause. 

Sectional Cause:Sectional Cause groups aim to protect a section of society. For instance, Shelter protects the homeless by increasing funds for homeless shelters and soup kitchens.

Attitude Cause: Attitude Cause groups aim to change peoples views on a certain issue. For example, Greenpeace aim to change peoples views on the environment, to care more for it.

Similarities: 

Ways to express opinion

Outlets for political participation, especially through membership

Role in workings of government, especially close insider groups

There can be close relations-TUs with the Labour Party, Electoral Reform Society with the Liberal Democrats

Differences: 

Do not seek to win elections and form a government

Do not attempt to advance ideas covering ALL public policy

Some aspirations may be non-political

4 Methods Pressure Groups Use to Achieve Their Goals

Pressure groups (also known as interest groups) are known to adopt a variety of tactics to get what they want from their employers, public officials or the government.

Below are four measures a pressure group can use to achieve its objectives.

1. Political appointment

Pressure groups often sponsor their sympathizers or active members to contest for public office. This is to allow them to be well…