The relationship between political parties and pressure groups can take different forms.
(i) Pressure groups are often formed and led by politicians and political parties. Most trade unions and students’ organisations in India are either established by, or affiliated to one or the other major political party.
(ii) Political parties sometimes grow out of movements. Parties like DMK and AIADMK were formed this way.
(iii) Many a times, the issues raised by pressure or movement groups are taken up by political parties, leading to a change in the policies of the parties.