Environmental Resources Management (ERM) has provided independent third-party assurance over selected sustainability content of the 2017 Integrated Annual Report. The assurance was conducted in line with the AccountAbility AA1000 Assurance Standard (Revised, 2008) (Type I Moderate level). The engagement was conducted using the AA1000 AccountAbility Principles Standard (2008) criteria and those of the GRI Standards Sustainability Reporting Guidelines. For the detailed assurance statement refer to: