Louise Mensch's political career is, to a considerable extent, defined by Twitter. She broke from backbench anonymity to the political spotlight partly through her use of the social media site and has even launched a wannabe competitor, in the laughably named 'Menshn'. Her success on the site comes down to her independent political views and jargon-free writing style. The former quality has taken something of a knock recently, as the MP offers increasingly party-political views on the site, often attracting mockery for the how far she will go to defend ministers in trouble. But her willingness to retweet some of the misogynistic abuse thrown her way opened up a debate about behaviour online and the treatment of female political figures which Twitter and Facebook badly needed to have. The Corby MP is as frustrating and unreliable as it gets, but she is still a vital and impressive presence online.