2015 United Kingdom general election in Scotland

Since 2005, the Scottish National Party had come first in the 2007 Scottish Parliament election as well as the 2009 European Election. In Westminster, however, it was a different story; although the party won the Glasgow East by-election in 2008, which was one of the safest Labour seats in the UK, by the time of the 2010 UK election and even with an increase of 2.3% in the vote, it only managed to retain the seats it won in the 2005 election. A year later in the 2011 Scottish Parliament election the SNP became the first majority government since the opening of Holyrood, a remarkable feat as the mixed member proportional representation system used to elect MSPs makes the acquisition of a one-party majority challenging. The SNP gained 32 constituencies, 22 of which came from Scottish Labour, nine from the Scottish Liberal Democrats and one from the Scottish Conservatives. Such was the scale of their gains that, of the 73 constituencies in Scotland, only 20 were represented by MSPs of other political parties in 2011.

The SNP's majority in the Scottish Parliament allowed it to legislate for a referendum on Scottish independence. This was held in 2014, and the proposal for independence was defeated by 10.6 percentage points. In spite of this, the campaign in favour of independence made a set of significant in roads across the central belt of Scotland, a region which has traditionally had a strong affiliation with the Labour Party. The Yes campaign took 44.7% of the vote in Scotland on a high turnout of 84.6%: well beyond the SNP's 19.9% vote share at the 2010 UK general election. This took form at the 2015 UK general election with a saturation of the SNP vote in areas which had a higher "Yes" vote at the 2014 Scottish independence referendum.

Scottish Labour had held the majority of seats in Scotland in every general election since the 1960s. This is usually attributed to the North-South divide in British politics, where Scotland and Northern England tend to return mostly Labour MPs whereas the South of England tends to vote mostly for the Conservatives. Many prominent government officials represented Scottish constituencies, such as the Prime Minister Gordon Brown and the Chancellor Alistair Darling. In the 2010 election, the Labour Party in Scotland increased its share of the vote by 2.5% and re-gained the Glasgow East and Dunfermline and West Fife constituencies giving them 41 out of 59 seats in Scotland. At the 2011 Scottish Parliament election, Labour lost out to the SNP across much of the central belt of Scotland, holding on to 15 out of 73 constituency seats in Scotland.

In 2015 Labour lost 40 of its 41 Scottish constituencies at the UK Parliament, with Edinburgh South becoming the only constituency in Scotland to have a Labour MP after the election. The party lost out heavily to the SNP in working class areas around central Scotland, with Scottish Labour's safest constituency (Glasgow North East) returning the largest swing in the election at 39.3% from Labour to SNP. The party performed best in its more affluent constituencies, with Scottish Labour's leader Jim Murphy missing out in his former constituency of East Renfrewshire by just 6.6% of the vote. Labour's next closest constituency result came in Edinburgh North and Leith, where the missed out to they SNP by 9.6% of the vote, and in East Lothian, where the SNP polled ahead of Labour by 11.5% of the vote.

The Scottish Liberal Democrats lost 10 of its 11 Westminster constituencies from 2010, with its safest constituency in Great Britain - Orkney and Shetland - becoming the only Liberal Democrat constituency in Scotland. They marginally lost out to the SNP in East Dunbartonshire, where former Lib Dem MP Jo Swinson lost out to the SNP by 4% of the vote. Among those to lose their constituency at the election were former Liberal Democrat leader Charles Kennedy and the Chief Secretary to the Treasury, Danny Alexander. The Liberal Democrats came third in Berwickshire, Roxburgh and Selkirk and West Aberdeenshire and Kincardine, constituencies which they had held in the previous election.

The Scottish Conservatives have not held a majority of Scottish seats in a general election since 1955 and it lost all eleven of its seats in the election of 1997. From 2001 until 2017, the party only held one Westminster seat in Scotland. In 2005, following the re-organisation of Scottish constituencies, that seat was Dumfriesshire, Clydesdale and Tweeddale, a mostly rural constituency near the Scottish borders. In 2010 its share of the vote in Scotland increased by roughly 0.9% and it retained the Dumfriesshire, Clydesdale and Tweeddale, as its only Scottish constituency. It had been reported the party could gain Berwickshire, Roxburgh and Selkirk,[7] a seat which they lost out on to the SNP by 0.6% of the vote.

Minor parties such as the UKIP and the Scottish Greens announced that they would contest more Scottish seats than they did in the 2010 election. UKIP targeted the sole Conservative seat in Scotland, as well as standing candidates in several others. The British National Party also announced its intention to contest more seats than in 2010, though in the event did not stand a single candidate in a Scottish constituency.[8][9] The Scottish Socialist Party stood in four constituencies.[10]

The prospect of an electoral alliance between pro-independence parties—specifically the SNP, the Greens, and the Scottish Socialist Party—was raised after the referendum and supported by elected SNP politicians,[11] but played down by Green co-convenor Patrick Harvie, who said party members did not want their "distinctive Green perspective" to be lost.[12] The SSP supported negotiations for a formal alliance until late in 2014.[13][14]

• 31 March – The first official day of the election campaign got under way, with the Scottish Greens becoming the first party to launch their manifesto.[15][16]
• 7 April – First TV debate was broadcast on STV[17]
• 8 April – Second TV debate was broadcast on BBC Scotland, with UKIP and the Scottish Greens included.
• 10 April – Ed Milliband visits Edinburgh, claiming the SNP's aim to have full control of tax in Scotland would create a £7.6bn financial "black hole".[18][19]
• 12 April – Third TV debate was broadcast on BBC Scotland, between the four main parties. The debate was criticised, with many of the public claiming it was a "Rammy".[20][21]
• 21 April – Sir John Major entered into the row, and repeated claims by David Cameron that an Labour-SNP government would be a "recipe for mayhem" and entering blackmail.[22] A number of former Conservative ministers entered into the debate claiming deep unease about the rhetoric. Lord Tebbit described Cameron's repeated warnings about the SNP as "puzzling" and "pointless", and might even push Scots to vote tactically for Labour.[23] Lord Forsyth claimed it was playing a "short term and dangerous game" which could further threaten the union.[24][25][26] Ed Miliband rejected the claims, while Nicola Sturgeon labelled Sir John's comments as "Silly over the top and an affront to democracy".[27]
• 4 May – Scottish Labour leader Jim Murphy and comedian Eddie Izzard were heckled by opponents while campaigning in Glasgow city centre, with the scene descending into scuffles. SNP leader Nicola Sturgeon condemned the scenes but said they had "nothing to do with the SNP".[28][29][30][31] The following day the SNP placed two members under "administrative suspension".[32][33]

• 2015 United Kingdom general election in England
• 2015 United Kingdom general election in Northern Ireland
• 2015 United Kingdom general election in Wales