The Campaign Guide was an important compendium of facts and figures published by the Conservative Party in preparation for an election campaign. It provided the background for all important political questions of the period, as well as a full record of the performance of the Party as compared against the Opposition during the life of the previous Parliament. Each Guide is fully indexed by subject and contains a full conspectus of events and review of problems for each parliament, with extensive essential background information and appendices.

Although a volume entitled Campaign Notes was produced by Conservative Central Office in London in 1885, the first Campaign Guide proper was produced by the Council of the National Union of Conservative Associations for Scotland in Edinburgh in 1892. Subsequent editions up to 1909 were also published in Edinburgh but thereafter publication was taken over by Conservative Central Office. Production delays which meant the 1922 edition came out too late for the election also resulted in no Guide being produced for either the 1923 or 1924 elections, but it was revived in 1929 under the title Election Notes for Conservative Speakers and Workers. In 1931, 1935 and 1945 it was published under the title Notes for Speakers and Workers. In 1948 the Reference and Political Section at Central Office was transferred to the Conservative Research Department, and production of the Campaign Guide transferred with it, although the imprint on the title page continued to be that of Central Office. It was at this time that publication reverted to the title Campaign Guide for the 1950 and subsequent editions to date.

The Campaign Guide was intended to be published just a few months before an election campaign began, but often this was difficult to predict. After the Second World War if much time elapsed between the appearance of the Campaign Guide and the announcement of the General Election, a Campaign Supplement was produced. Since 1979, similar volumes have also been produced for the direct elections to the European Parliament.

Whilst the guides are primarily designed for the Party's own candidates and officials, they are not confidential and are available to the press and other interested observers. The Campaign Guide is the Party's 'bible': the authoritative source for definitions of policy and for checking the terms of statements which have been made. When the Party has been in power, it provides a defence of the Conservative record with supporting statistics and examples; when their opponents have been in office, it offers chapter and verse on their failings.

The Campaign Guide is not a series of pledges or the official statement of the Party's programme: that is the role of the Manifesto. However the latter is brief and often deliberately kept to vague generalities, and it is the Campaign Guide which puts flesh on the bones. In practice - at least unofficially - it has come to be regarded as a supplement to the manifesto. As it is in the public arena and the Party can be challenged upon its contents, it is carefully drafted, rigorously checked, and quoted passages are buttressed by attribution or source. The guide is normally prefaced by an introduction from the Party leader which summarises the main planks of the programme and aims to set the tone of the campaign.