Gregory was called to the Bar Lincoln’s Inn (1991), KC (2011), called to the Bar King’s Inns (1997), and called to the Bar of Northern Ireland (2008). He is a member of the Irish Planning and Environmental Bar Association, and is an LA(RTPI).
Gregory’s expertise includes town & country planning, environmental, ESG, EU, compulsory purchase, administrative and local government law. He is a Fellow of the Centre of European Law, King’s College, London, a Fellow the Royal Geographical Society, a Distinguished Visiting Fellow of St. Stephen’s House, Oxford University, and a Law Fellow of Goodenough College.
Gregory is one of the very few specialists in town and country planning and environmental law practising in three jurisdictions (IRE, ENG & WALES and NI). This provides added value by enabling Gregory to draw upon his experience and apply persuasive case law of the different jurisdictions when advising clients. This is particularly useful in EU environmental and planning law in which he is an acknowledged expert.
Gregory has appeared in many leading EU planning and environmental cases before national courts as well as the Court of Justice of the European Union. He has gathered an intimate knowledge of how EU institutions work having worked as a stagiaire at the European Commission and as Jean Pierre Warner at the European Court of Justice. He is the Editor of several leading EU environmental law texts including: ‘The Habitats Directive: A Developer’s Obstacle Course‘ and ‘The Strategic Environmental Assessment Directive: A Plan for Success?‘
Gregory’s cases in Ireland include acting for the Cork Oyster Bay Co in its long running litigation over pollution of Cork Harbour and acting for a major international clothing manufacture on waste recycling. In 2015, Gregory was appointed by the Irish government to chair an independent review of An Bord Pleanála which reported in February 2016. In 2020 Gregory was appointed to the Court of the Honourable the Irish Society, and in 2023 Gregory was appointed to the Diocesan Court of Dublin: Panel of Counsel – an Advocate to the Court.
Gregory’s recent publications include writing the chapter on comparisons of approaches in England, Northern Ireland and Ireland on Habitats Assessments in Nature Law and Policy on Europe (edited by Andrew Jackson) and an opinion Editorial in The Irish Times 19 July 2023: ‘How to reform the Irish planning system in three steps’.