Many primary resources for politics are freely available online as well as in print. Below are some examples of resources available from national and international government bodies.
The United Kingdom
There is no single collection of political party manifestos in Cambridge, but there are several scattered throughout the different libraries. For specific manifestos, search the name of the party and year of publication along with a keyword (like 'manifesto') in iDiscover. The manifestos of the three major political parties have been collected in books which are held in the University Library and elewhere:
American Platforms (party and presidential)