For many years now commentators have been predicting the UK's first 'Internet Election'. This thesis seeks to cut through the hype by measuring the precise extent of online campaigning by electoral candidates during the 2010 general election campaign. It does so by using an original and extensive dataset that captured personal website adoption and the use and content of social media and email. Data was collected directly from the websites and Web 2.0 tools used by candidates during the campaign and from a quasi-experimental email study involving contacting candidates. By assessing online campaigning from an elite perspective the thesis can engage with key debates prominent in the literature on online campaigning.The thesis poses three questions. The first question asks whether the Internet has become a mainstream campaigning tool for electoral candidates in the UK. The second question focuses on whether the Internet is allowing minor parties to compete on a more equal footing campaign-wise with their major counterparts, which feeds into the debates concerning normalisation or equalisation between competing political parties and candidates. The third question relates to the content of the online campaigns of candidates, and whether the Internet may be changing campaign styles in terms of moving them from a top-down 'broadcast' mass mobilisation model towards a more interactive and engaged form of campaign communication.The findings suggest that although social media was not used widely, personal websites and email use were relatively common. In assessing inter-party competition in online campaigns the thesis finds that although candidates standing for larger parties were more likely to have personal campaign websites, the other online campaign tools assessed here, social media and email, were found to be more equalised on some measures between candidates from major and minor parties. Finally, when assessing the content of social media and email use by candidates, the evidence suggests that online tools may be facilitating a move towards more open and engaged campaign communication. Broadcast mode social media campaigning, where candidates did not accept or respond to comments, was relatively rare. Moreover, candidates who did reply to the hypothetical voters email tended to provide personalised and engaged content rather than solely electioneering. Overall, the findings suggest that although online campaign tools have not thus far led to a huge change in campaign communications, it is leading to a small shift towards more equalised and engaged campaigning.