The regulation of party political funding and expenditure in the United Kingdom is an issue of continuing political and public debate. Campaign expenditure by candidates has been regulated since the late nineteenth century, but this has applied only during the short campaign period between the dissolution of Parliament and polling day. Concerns have been raised about earlier expenditure levels, but these were not regulated until legislation in 2009 which limits the amount that candidates can spend in the months prior to Parliament's dissolution—in 2010 this covered the period between 1 January and 15 April: the election was held on 6 May. The Electoral Commission has released information on all candidates who made a return of their expenditure during both periods. This article provides descriptive data on those amounts, by party and type of constituency, plus analyses which show that the more that a party spent the better its performance at the polls.