than listing the matters over which the Scottish Parliament does control (devolved powers), it specifies the matters over which it does not (reserved matters). It further designates a list of statutes which are not amenable to amendment or repeal by the Parliament which includes the Human Rights Act 1998 and many provisions of the Scotland Act itself. Even when acting within its legislative competence, the Act further constrains the powers of the Parliament by inhibiting it from acting in a manner incompatible with the European Convention on Human Rights or European Community law. The same constraints apply to acts of the Scottish Executive. The Act grants the Secretary of State for Scotland power to direct the Scottish Government not to take any action which he has reasonable grounds to believe "would be incompatible with any international obligations" or to act where he believes such action "is required for the purpose of giving effect to any such obligations". The Act also sets up mechanisms to resolve disputes over questions about legislative competence of the Parliament and powers of the Executive. The ultimate appeal in such matters lies to the Supreme Court of the United Kingdom (prior to 1 October 2009, the Judicial Committee of the Privy Council). In exceptional circumstances, the Westminster government can prohibit an Act of the Scottish Parliament — even if legislatively competent — from receiving royal assent if it believes the law would affect matters of reserved law; this provision has been only used once, to veto the Gender Recognition Reform (Scotland) Bill in 2023. The Act also allows the powers of the Scottish Parliament and the Scottish Executive to be adjusted over time by agreement between both Parliaments by means of an Order in Council. The Act was passed on 17 November 1998, and received royal assent two days later on 19 November. The first elections were held in May 1999 and the Scottish Parliament and Executive assumed their full powers on 1 July 1999. Amendments to the Act The Act was amended by the Scottish Parliament (Constituencies) Act 2004 to end the link between the number of MPs at Westminster and the number of constituency MSPs. It was amended again in 2016 as a reaction to the 2014 Scottish Independence vote. The Wales Act 2014 made amendments to Part 4A of the Scotland Act around the definition of a Scottish taxpayer, to ensure that an