The government is publishing a response to its consultation on a UK ivory sales ban, and confirming "robust measures" that will be brought into force. The ban will cover ivory items of all ages which will make the UK's ban one of the toughest in the world. In line with the approach taken by other countries, including the USA and China, there will be certain narrowly-defined and carefully-targeted exemptions for items which do not contribute to the poaching of elephants.

As part of the UK government's consultation process Penelope Nevill was instructed by the NGO Stop Ivory, in a team led by Mishcon de Reya and working with an NGO coalition including the ZSL, IFAW and other leading environmental organisations, to advise on various issues to assist Stop Ivory's campaign. Advisory issues included the public international law and EU law related aspects of their questions and proposals, such as treaty interpretation and treaty amendment processes, the operation of international treaties relevant to wildlife protection and trade. This included the convention on the international trade in endangered species (CITES), the Bonn Convention, and the convention on biological diversity and the implementation of CITES into EU and UK law.

Penelope also advised a second report in 2017 focusing on changing UK regulations implementing EU regulations which in turn implemented CITES, and the relevance of EU law pre-Brexit and property rights. The second report was widely circulated and relied on by Lord William Hague in his capacity as the Chairman of the Duke of Cambridge's task force on illegal wild life trade and featured prominently in the press in Autumn 2016.