Gordon Brown announces that the Bank of England, central bank of the UK, is to assume independent responsibility for UK monetary policy. 19 May – The new Labour government announces that it will ban tobacco sponsorship of sporting events. June June – Ford enters the growing compact coupe market with its Puma, which uses the same chassis as the Ka and Fiesta. 2 June – The Halifax Building Society floats on the London Stock Exchange. Over 7.5 million customers of the Society become shareholders of the new bank, the largest extension of shareholders in UK history. 12 June – Law Lords declare that former Home Secretary, Michael Howard, acted illegally in raising the minimum sentence of the two juveniles who committed the murder of James Bulger, Robert Thompson and Jon Venables, to 15 years. They also strip the government of setting minimum terms for prisoners aged under 18 who had received life or indefinite prison sentences. 19 June The High Court of Justice delivers judgement, largely in favour of McDonald's, in the libel case of McDonald's Corporation v Steel & Morris ("the McLibel case"), the longest trial in English legal history, against two environmental campaigners. William Hague is elected as the leader of the Conservative Party. 23 June – Construction begins on the Millennium Dome. 25 June – An auction of dresses owned by Diana, Princess of Wales, in Manhattan raises more than £2 million for charity. 27 June – Publication of J. K. Rowling's first Harry Potter novel, Harry Potter and the Philosopher's Stone. July 1 July – The UK transfers sovereignty of Hong Kong, the largest remaining British colony, to the People's Republic of China as the 99 years lease on the territory formally ends. This event is widely considered by historians and commentators to mark the end of the British Empire, the largest imperial endeavour in the history of mankind. 2 July – Chancellor Gordon Brown launches the first Labour budget for nearly 20 years, which includes a further £3billion for education and healthcare, as well as a £3.5billion scheme to get single mothers, under 25's and long term unemployed people back into work. 4 July – Russian carmaker Lada announces the end of imports to the United Kingdom after 23 years and some 350,000 sales of its low-priced, low-specification cars, which at their peak sold more than 30,000 cars a year but managed just over 6,000