Voting took place between 17 November and 10 December using the three-tier electoral college system, which gives parliamentarians, individual members, and affiliated bodies such as trade unions an equal say in the outcome.

Controversy ensued when the Unite trade union issued a mock ballot paper instructing members on which candidates to elect, and when two prominent Labour figures engaged in an argument about the contest on social media.

Although Murphy subsequently said that he wished to remain as Scottish Labour leader, the poor result prompted senior party figures and trade unionists to question the viability of his future in the post.

[1] The Scotsman's Euan McColm wrote that although Lamont was given greater autonomy over Labour in Scotland, her Westminster colleagues "restrained" her attempts to develop a devolution policy, and her debate on universal benefits resulted in the SNP portraying her as "a politician dedicated to seizing from the people that which was rightfully theirs".

The Daily Telegraph's Alan Cochrane wrote that many Labour MPs in Scotland feared losing their seats in the 2015 general election without a change of leadership.

Paul Hutcheon noted in the 9 November edition of the Sunday Herald that Labour had "consistently declined" to confirm the number of its members in Scotland, but quoted an "informed source" suggesting the figure was slightly short of 13,500.

[2] Shortly afterwards, his predecessor, Henry McLeish suggested Labour had ceded "enormous ground to the SNP unnecessarily" because its supporters no longer understood "what the party stands for".

[19] The New Statesman claimed that Labour had spent "decades treating Scotland as little more than a one-party state" and needed to "[make] itself relevant again for the people whom it was established to represent".

[20] Stephen Daisley, political editor of STV News, suggested that Labour had "responded to the Nationalist advance by electing a succession of decent but ineffectual Holyrood leaders who were dominated by the Westminster party machine".

[28] Explaining this decision on the day the contest was announced, Sarwar told BBC News, "We have had unanimous agreement to get the balance right between moving quickly to elect a new leader and also allowing a period of time to have an open, frank and honest debate about the future direction of the Scottish Labour party.

[24] Neil Findlay and Michael Connarty, the MP for Linlithgow and East Falkirk, both urged former Prime Minister Gordon Brown to enter the race, but he declined.

[24][45][46] Other potential candidates who decided not to run were Sarwar, who wished to concentrate on plans for the next general election, and Baillie, Holyrood's Shadow Health Secretary, who said she wanted a "supporting role" rather than to be Labour leader.

[55] He was also endorsed by Neil Kinnock, a former leader of the UK Labour Party, who donated an undisclosed sum of money to Murphy's campaign,[56] and by Shadow Scottish Secretary Margaret Curran.

[b][62][63] He further said that he would introduce a 50 per cent top income tax rate for earners above £150,000[64] and devolve some welfare responsibilities handed to Holyrood by the Smith Commission, such as the Work Programme, to local authorities.

[10] On education, he pledged to create a facility to promote good teaching practice, introduce chartered status for teachers, and identify and provide support to secondary schools that were deemed to be failing.

[72] Positioning herself as a unifying candidate who would make the party "fit for purpose", she called for "bold and radical" new approaches to policy, which would require Labour to be honest about funding crises in local government and health.

[74] Boyack said that as leader, she would campaign on better funding for healthcare, improvements to childcare, education and youth employment opportunities, and the devolvement of power to local government.

[78] Subsequently, appointed as Shadow Health Minister, he was also a member of the Red Paper Collective, a group of politicians who called on Labour to support the full devolution of income tax powers to Scotland.

[83] Among his plans for devolution was for Holyrood to have power over employment regulations to enable the creation of a Scottish Health and Safety Executive and the introduction of corporate culpable homicide legislation.

[71] Dugdale talked of improving employment, wages, education, and childcare, saying that she stood for "tomorrow's Scotland – a country free from poverty and injustice, with opportunity for everyone".

[87] The Ardrossan and Saltcoats Herald reported that as a parliamentarian, she developed a reputation as a party rebel who, at the time of the leadership contest, had most recently voted against British participation in the 2014 military intervention against the Islamic State of Iraq and the Levant.

"[87] Policy areas she intended to focus on included improvements in employment, housing, and public services, which she said were "prevented for too many by wealth being held in the hands of a minority.

[94] Following a Sunday Herald article in which the Labour MP Tom Watson suggested Murphy's election would be "disastrous" for the party, he and Ivan Lewis, the Shadow Secretary of State for Northern Ireland, engaged in a heated exchange on Twitter during which Lewis accused Watson of manipulating past UK Labour leadership contests and of wanting to influence the election of the party's next Scottish leader.

[97] On 10 December, David Robertson, the moderator-elect of the Free Church of Scotland, expressed concerns that Murphy had been subject to religious discrimination after Gary Otton, leader of the Scottish Secular Society, posted several threads on Facebook commenting on the leadership candidate's Roman Catholic faith and his support for denominational schools.

"[102] In what a Scottish Labour spokesman described as a bid to "encourage transparency", the party took the decision to publish details of how its parliamentarians had voted during the ballot, a process that had previously been kept private.

[110] Those results showed that the parliamentarians who chose Murphy as their first candidate included Baillie, Brown, Curran, Dugdale, Gray, Kelly, Marra, and Sarwar.

The MSPs Claudia Beamish, Rhoda Grant, and Lewis Macdonald were among those to vote for Boyack, while Findlay was backed by Clark, Ian Davidson, and Lamont.

[111] The full results of the leadership contest were as follows:[104][105][107] Speaking to BBC Radio 5 Live following his election, Murphy said that while he disagreed with the "branch office" theory, he would not be consulting London on policy: "[t]he days in which anyone needed permission from the Labour Party anywhere else in the United Kingdom to make a decision about what happens in Scotland are gone and they're gone for good.

"[113] On the 14 December edition of BBC One's Sunday Politics Scotland, he repeated his pledge to seek election to the Scottish Parliament, and said that he was "determined" to retain every Westminster seat held by Labour.

Other appointments to Labour's frontbench team were Mary Fee (Infrastructure, Investment and Cities), Gray (Education and Lifelong Learning), Ken Macintosh (Social Justice, Communities and Pensioners' Rights), Hugh Henry (Justice), Claire Baker (Culture, Europe and External Affairs), Kelly (Parliamentary Business Manager), Neil Bibby (Chief Whip), and Graeme Pearson (Enterprise).