This article examines the reverse legal burden of proof upheld by the House of Lords in Sheldrake v The Director of Public Prosecutions [2004] UKHL 43 in relation to the offence ‘being drunk in charge’ of a motor vehicle, contrary to the Road Traffic Act 1988 s.5(1)(b), and the defence under s5(2). It considers two main arguments that arose from Sheldrake. First, that the section 5(2) defence that there was no likelihood of the defendant driving while over the limit forms part of the gravamen of the section 5(1)(b) offence and that, accordingly, a reverse legal burden amounts to a breach of the presumption of innocence. It is argued that this analysis, approved by the Divisional Court but largely overlooked by the House of Lords, is per Lord Bingham “too simple and only partially correct”. Secondly, it will be considered whether some offences, such as ‘being drunk in charge’, may be classified as regulatory on the basis that the offence was concerned with a lawful activity that the defendant voluntarily engaged in that presented a serious risk or danger to public health and safety. It is argued that in this context a reverse legal burden may normally be presumed.