16. The Parties recognise that they have a particularly important trading and investment relationship, reflecting more than 45 years of economic integration during the United Kingdom's membership of the Union, the sizes of the two economies and their geographic proximity, which have led to complex and integrated supply chains. 17. Against this backdrop, the Parties agree to develop an ambitious, wide-‐ranging and balanced economic partnership. This partnership will be comprehensive, encompassing a free trade area as well as wider sectoral cooperation where it is in the mutual interest of both Parties. It will be underpinned by provisions ensuring a level playing field for open and fair competition, as set out in Section XIV of this Part. It should facilitate trade and investment between the Parties to the extent possible, while respecting the integrity of the Union's Single Market and the Customs Union as well as the United Kingdom's internal market, and recognising the development of an independent trade policy by the United Kingdom beyond this economic partnership. 18. The Parties will retain their autonomy and the ability to regulate economic activity according to the levels of protection each deems appropriate in order to achieve legitimate public policy objectives such as public health, animal health and welfare, social services, public education, safety, the environment including climate change, public morals, social or consumer protection, privacy and data protection, and promotion and protection of cultural diversity. The economic partnership will recognise that sustainable development is an overarching objective of the Parties. The economic partnership will also provide for appropriate general exceptions, including in relation to security. 19. The Parties recall their determination to replace the backstop solution on Northern Ireland by a subsequent agreement that establishes alternative arrangements for ensuring the absence of a hard border on the island of Ireland on a permanent footing.