Interest groups are not directly involved in electoral contests. Their purpose is to influence public policy and the election results. These groups may be interested in a particular election issue, or in a candidate or political party sharing their views. Groups vary in size, resources, power and objectives, but all use the same methods to influence public opinion and promote their position—including lobbying, campaigning, advertising through the mass media, and providing information to candidates, lawmakers and policy makers.

This section discusses interest groups that champion personal, economic or material interests. Public interest groups that act on behalf of the public are discussed in Non-Governmental Organizations.

Interest groups may play a positive role in maintaining election integrity since they monitor the process to ensure that opposing interests do not receive preferential treatment. However, the vast amount of money that interest groups today spend to sway public opinion raises many integrity issues. These are discussed in greater depth in Campaign Financing.

Most interest groups hire professional lobbyists who focus on promoting the priorities of the group that hired them; these do not necessarily coincide with the public interest. Lobbyists spend money to influence decision makers; they also help candidates and parties supporting their views to win election. Lobbyists may entertain candidates and policy makers at expensive restaurants or weekend getaways. They may use money to place advertisements in the media supporting a particular campaign or position.

The amount of money spent and how it is spent can raise concerns that interest groups are buying influence and special treatment. As a result, most countries require interest groups to register and disclose their activities and spending.

Although interest groups may be highly partisan and interested solely in promoting their own priorities, they must still abide by the same standards of ethical conduct as other participants in the electoral process.