Events
January
4 January – Sir Tim Barrow is appointed as the UK's new ambassador to the European Union. 9 January – Northern Ireland's Deputy First Minister Martin McGuinness resigns. 16 January – The power-sharing government of Northern Ireland collapses following the resignation of Martin McGuinness. 24 January – The UK Supreme Court rules against the Government's Brexit appeal case by an 8 to 3 decision, stating that Parliament must vote to trigger Article 50. 30 January – A petition to stop US President Donald Trump's UK state visit gathers more than 1.8 million signatures.
February
1 February – MPs back the European Union Bill by 498 votes to 114, with 47 Labour rebels voting against. 3 February – The government publishes a white paper setting out its Brexit plans. The 2017 Copeland by-election is held. Conservative candidate Trudy Harrison gains the seat from Labour, the first gain for a governing party in a by-election since 1982. Labour win the Stoke-on-Trent Central by-election. 8 February – Labour MP Clive Lewis resigns from the Shadow Cabinet in protest over his party's decision to whip its MPs into voting to trigger Article 50. 22 February – The British government confirms that in future MPs will be able to use the Welsh language during meetings of the Welsh Grand Committee. 23 February – By-elections are held in Copeland and Stoke-on-Trent Central to fill vacancies arising from the resignation of sitting Labour MPs. Trudy Harrison wins the Copeland seat for the Conservative Party and Gareth Snell retains the Stoke-on-Trent Central seat for the Labour Party. Labour had held the Copeland seat since its creation, and the Conservative win is the first gain by a serving government in a by-election for 35 years.* 26 February – Father of the House of Commons and veteran Labour MP Gerald Kaufman passes away at the age of 86.
March
2 March – New elections to the Northern Ireland Assembly are held. The Democratic Unionist Party loses ten seats, while Sinn Féin loses one seat. 8 March Philip Hammond delivers the March 2017 United Kingdom budget, his first as Chancellor of the Exchequer. Lord Michael Heseltine is sacked from his role as a government adviser following his rebellion against the government on the Brexit Bill in the House of Lords the previous day. 14 March – The British Parliament passes the Brexit bill, paving the way for the UK Government to trigger Article 50; so that the UK can formally withdraw from the European Union. 15 March – Chancellor of the Exchequer Philip Hammond is forced to make a U-turn on his commitment to raising National Insurance contributions for the self-employed after vast opposition from Conservative backbenchers. 16 March The European Union (Notification of Withdrawal) Bill is given Royal Assent by HM The Queen, making it an Act of Parliament. Theresa May formally rejects Scottish First Minister Nicola Sturgeon's second Scottish Independence Referendum timetable for Autumn 2018, or at least before Brexit negotiations are concluded. 29 March – The United Kingdom invokes Article 50 of the Treaty on European Union, beginning the formal EU withdrawal process.
April
6 April – Mark Reckless AM quits UKIP and will now support the Conservative Party group in the National Assembly for Wales. 8 April – Robin Swann is announced as the new Ulster Unionist Party leader. 18 April – Prime Minister Theresa May calls a snap general election for 8 June. 19 April – The House of Commons formally approves the calling of an early general election with the necessary two-thirds majority in a 522 to 13 vote. 20 April – The 2017 Manchester Gorton by-election is cancelled following the announcement of an impending general election. This was the first time a UK by-election had been cancelled since 1924.
May
4 May
Buckingham Palace announces that the Duke of Edinburgh is to step down from carrying out royal engagements in the autumn. Local government elections are held across England, Scotland and Wales. The Conservative Party makes significant gains at the expense of the Labour Party, gaining 500 seats and seizing control of 11 councils. UKIP loses all 145 seats they were defending. The Liberal Democrats lose 41 seats, despite their share of the vote increasing. Labour is pushed into third place by the Conservatives in Scotland, where the SNP is comfortably the largest party despite failing to take control of target councils. The Conservatives win four out of six metro-mayoral areas, including in the traditionally Labour-voting Tees Valley and West Midlands. 23 May – General election campaigning from all major political parties is temporarily suspended after the previous day's attack in Manchester.