The Conservatives needed a net gain of 116 seats at the 2010 general election if they were to win an overall majority and form the next government. From 2007 onwards, a unit in the central party organization, led by Conservative Deputy Chairman Lord Ashcroft, worked with local parties to promote their candidates' cause in a substantial number of marginal constituencies. The efforts of Lord Ashcroft's team involved the expenditure of several million pounds during the pre-election campaign period in an effort to win over voters in key battleground seats. But was it effective? Using a path modelling approach, we provide substantial evidence that it was. Not only did it have both a significant direct effect and an indirect effect, through "short campaign" effort, on Conservative Party support in 2010, but the Conservatives were significantly more likely to win key battleground seats against Labour where larger grant allocations were made. Frequency also mattered. The Conservatives were far more likely to win Labour-held seats if constituencies received money from Lord Ashcroft's team on two or more occasions.