Events from the year 2004 in the United Kingdom.

Incumbents Monarch – Elizabeth II Prime Minister – Tony Blair (Labour)

Events January 1 January – Papers released under the Thirty-year rule reveal that, contrary to what was believed at the time, Princess Margaret would not have lost her title nor Civil list payments had she married Group Captain Peter Townsend, a divorced War hero, in the 1950s. 3 January – The BBC cancels the appearance of Coca-Cola sponsorship credits in the music charts on its BBC One Top of the Pops show, after criticism from politicians and health campaigners that it would be promoting junk food and unhealthy drink products to teenagers. 6 January The coroner's inquest into the death of Diana, Princess of Wales and her lover Dodi Al-Fayed is officially opened. The Daily Mirror publishes the blacked out portion of a letter wherein Diana, Princess of Wales alleged that someone was trying to kill her. 7 January – It is announced that a record of nearly 2,600,000 new cars were sold in the United Kingdom during 2003. 8 January – is christened by Elizabeth II. 13 January Labour politician Robin Cook says that the British Museum's Parthenon Marbles should be returned to Greece. Serial killer Dr. Harold Shipman is found dead in his cell one day prior to his fifty-eighth birthday following his suicide by hanging. The Bichard Inquiry into events preceding the Soham murders formally opens. 14 January – A 45-year-old Sudanese man travelling from Washington Dulles International Airport to Dubai Airport is arrested en route at London's Heathrow Airport on suspicion of carrying five bullets in his coat pocket. 19 January – The English Court of Appeal calls for an end to the prosecution of parents whose babies may have died of Sudden Infant Death Syndrome (cot death) in cases where the only evidence is contended expert testimony. 21 January – The Secretary of State for Defence publishes a White paper Delivering Security in a Changing World, detailing wide-ranging reform of the country's armed forces. 27 January – The vote of Scottish Labour MPs, whose constituents are unaffected by the legislation, help Prime Minister Tony Blair narrowly defeat a rebellion in his own party over the Higher Education Bill – a highly controversial bill to reform higher education funding in England, including the introduction of increased and variable tuition fees – in the House of Commons by 316 votes to 311. 28 January – The Hutton Inquiry into the circumstances of the death of Dr. David Kelly is published. This is taken by most of the press to be a strong condemnation of the BBC's handling of the affair and to exonerate the government; the BBC's Director-General, Greg Dyke, chairman of the Board of Governors, Gavyn Davies, and the journalist at the centre of the controversy, Andrew Gilligan, resign. The UK media, in general, condemns the report as a whitewash.

February 1 February – Media sources and victim support groups across Britain condemn the £11,000 payouts to the families of the two girls who were murdered at Soham in August 2002 as a "pittance". The compensation was paid out by the Criminal Injuries Compensation Authority. 3 February – Foreign Secretary Jack Straw announces an independent inquiry, to be chaired by Lord Butler, to examine the reliability of intelligence on weapons of mass destruction in Iraq. 5–6 February – A party of Chinese cockle pickers is caught by the tides at night in Morecambe Bay, Lancashire, drowning 23 people. 21 bodies are recovered. 11 February – Richard Desmond, the owner of the Daily Express and Daily Star tabloids, confirms that he has made a bid for the troubled broadsheet The Daily Telegraph. 15 February The government are reported to have drawn up plans to break up the BBC in the wake of the Hutton inquiry. Tebay rail accident: four railway workers are killed and five injured on the West Coast Main Line in Cumbria when a goods wagon carrying steel breaks loose from its train and runs backwards. 19 February – Foreign Secretary Jack Straw announces that five of the nine Britons held without trial as terror suspects at the Guantanamo Bay prison camp in Cuba, along with a Danish national, are to be released. 21 February – Prime Minister Tony Blair comes under pressure from British human rights groups and MPs because of the government's sweeping powers under the Anti-Terrorism Crime and Security Act, which have allowed the detention of fourteen foreign terrorist suspects in the UK at what has been described as "Britain's Guantanamo Bay". 24 February – The British Olympic Association prohibits European 100 metres champion Dwain Chambers from competing in the Olympic Games for life for a positive test for the designer steroid THG. 25 February – Katharine Gun, formerly an employee of British spy agency GCHQ, has a charge of breaching the Official Secrets Act dropped after prosecutors offer no evidence, apparently on the advice of the Attorney General for England and Wales. Gun has admitted leaking American plans to bug UN delegates to a newspaper. 26 February – Clare Short, former Cabinet Minister, alleges on the BBC Today radio programme that British spies regularly intercept UN communications, including those of Kofi Annan, the UN Secretary-General. 29 February – Middlesbrough F.C. win their first trophy in their 128-year history by defeating Bolton Wanderers F.C. in the Football League Cup Final.

March March – Vauxhall launches the fifth generation of its popular Astra family hatchback. It is initially available only as a five-door hatchback, with a three-door "Sporthatch" and a five-door estate due later in the year. 11 March – Support for the Conservatives and Labour is equal at 35% for the second time in nine months, raising the spectre of a hung parliament at the next general election which is expected within a year. 16 March – 15-year-old Scottish boy Kriss Donald is abducted, tortured and murdered by a Pakistani gang in a racially motivated attack in Glasgow. 21 March – Architect Zaha Hadid becomes the first female recipient of the Pritzker Prize. 28 March – The actor, author, diplomat and Chancellor of Durham University, Peter Ustinov, dies of heart failure aged 82 at a hospital in Switzerland. 30 March Operation Crevice, the arrest of a group of British Islamists, 5 of whom are subsequently convicted of conspiring to cause explosions likely to endanger life. The English-born American journalist Alistair Cooke dies of lung cancer at his home in New York City aged 95, only four weeks after his last broadcast of Letter from America.

April 19 April – In a change of government policy, Tony Blair announces there will be a referendum on the proposed EU Constitution. 28 April – Landmark office building 30 St Mary Axe ("The Gherkin") in the City of London, designed by Norman Foster, opens.

May 7 May – BBC Two airs The Simpsons for the final time with "Behind the Laughter" being the final episode, having lost terrestrial rights to air the show to Channel 4. 10 May – Maxine Carr is released from prison with a new identity after serving half of her sentence for perverting the course of justice in the 2002 Soham murders case, as announced on 6 February by the Home Office. 11 May – Stockline Plastics factory explosion: Nine people die in an explosion at a factory in Glasgow. 14 May – Piers Morgan is dismissed as editor of the Daily Mirror after the newspaper published fake pictures of Iraqi prisoner abuse. 15 May – Arsenal F.C. become the first team in history to win a Premier League undefeated. They are also the first to win a top flight title unbeaten since Preston North End in 1889. 19 May – Fathers 4 Justice stage a protest in the House of Commons at Prime Minister's Questions by throwing purple powder at Tony Blair. 22 May – Manchester United F.C. beat Millwall 3–0 in the FA Cup final. 27 May – The MP for Leicester South, Jim Marshall, dies triggering a by-election. 31 May – Long-running children's animated television series Peppa Pig premieres on the Nick Jr. Channel and Five.

June 2 June – José Mourinho, the Portuguese coach who led FC Porto to the UEFA Champions League title on 26 May, is named as the new manager of Chelsea F.C. on a three-year contract. 6 June – Sixtieth anniversary of D-Day. Last minute pressure forces First Minister of Scotland Jack McConnell to attend commemorations. Rhodri Morgan, the First Minister of Wales is criticised for not doing the same. 10 June A bumper election day takes place, dubbed "Super Thursday": 2004 United Kingdom local elections: Labour are dealt with significant blows, with a net loss of 464 councillors and 8 councils; while the Conservatives make a net gain of 13 councils and 288 councillors. There are mixed results for the Liberal Democrats as their vote share is down 3% and they lose 2 councils, but gain 123 councillors. 2004 European Parliament election: UKIP make big gains, gaining 10 seats bringing their total up to 12, indicating an increase in Euroscepticism; while both Labour and the Conservatives perform poorly, losing 6 and 8 seats respectively. 2004 London mayoral election: Ken Livingstone is re-elected as Mayor of London, beating Conservative rival Steven Norris in the second round of voting, albeit with a slightly reduced majority. 2004 London Assembly election: Labour and the Greens make losses, both the Liberal Democrats and UKIP make gains, while the Conservatives remain almost exactly level with the previous result. A rebranding of the Football League sees Division One become the Football League Championship, Division Two become League One and Division Three become League Two. 14 June – Results of the 2004 European elections are announced. UK Independence Party (UKIP) are the main gainers, increasing from 3 to 12 MEPs. 16 June – Liverpool F.C. appoint the Spaniard Rafael Benítez as their new manager. 21 June – The Football League club Wimbledon, who relocated to Milton Keynes from South London last autumn, are renamed Milton Keynes Dons to reflect their new location. 24 June – England are knocked out of UEFA Euro 2004 in the quarter-finals by host nation Portugal on penalties, following a 2–2 draw after extra time in Lisbon. 29 June – Islamic terrorist Kamel Bourgass, an illegal immigrant from Algeria, is convicted of the 2003 murder of Stephen Oake and the attempted murder of two other police officers. The crimes occurred in Manchester, with Oake stabbed eight times.R v Bourgass | EWCA Crim 1943 | England and Wales Court of Appeal (Criminal Division) | Judgment | Law | CaseMine

July 2 July An openly gay cleric, Jeffrey John, is installed as the Dean of St Albans. A court rules that Humberside Police Authority must suspend the Chief Constable, David Westwood, in accordance with the Home Secretary (David Blunkett)'s demands. Premier Travel Inn (shortened to Premier Inn in 2007) is formed by merger of the Travel Inn and Premier Lodge brands. 6 July – The Queen unveils the Diana, Princess of Wales Memorial Fountain in London's Hyde Park. 8 July – Marks & Spencer turn down a takeover bid by retail tycoon Philip Green. 12 July – Chancellor of the Exchequer Gordon Brown announces the massive loss of 100,000 civil service jobs in the UK; the savings to be put into frontline services such as Health and Education. 13 July The Public Administration Committee of the House of Commons recommends massive changes to the British Honours System including scrapping knighthoods and renaming the Order of the British Empire to the "Order of British Excellence". The Countryside Agency publicises a new Countryside Code in advance of the "Right to Roam" coming into effect in September across England and Wales. The House of Lords makes a hostile amendment to the Constitutional Reform Bill that would retain the name of the office of Lord Chancellor.