[6] From the start, most observers considered Brown the overwhelming favourite to succeed Blair; John McDonnell, his only challenger, failed to secure enough nominations in order to get onto the ballot, and conceded defeat.

The Labour Party and Blair himself subsequently experienced a surge in popularity at the time of terrorist bombings of London in July 2005, but by the Spring of 2006, were facing significant difficulties; most notably with scandals over failures by the Home Office to deport illegal immigrants and national campaigns by many political parties and think-tanks saying that the United Kingdom was being overrun by immigrants.

Worries over the potential increase of support for the far-right British National Party during the 2006 local election campaign saw many Labour backbenchers and activists begin to demand a timetable from Blair for his departure, with many suggesting that it should be sooner rather than later.

On 21 April, The Guardian reported that the Brown camp were working on the assumption that Blair would announce the candidacy open on 9 May 2007, the day after power-sharing was due to start in Northern Ireland, following which the new Labour Party leader would be elected on 15 July 2007.

[10] Talk of David Miliband, Alan Milburn,[11] Charles Clarke[12] or John Reid[13] as possible candidates was almost constant, although the former consistently denied any ambition to stand and the latter three refused to make a decision until there was a vacancy, ultimately declining in the week before Blair requested the NEC to find a successor.

Later, senior party members stated that Tony Blair would not be prime minister at the next Labour Party conference[14] and on 6 September, Tom Watson, one of the MPs who signed the letter, resigned as Junior Defence Minister[15] along with seven Parliamentary Private Secretaries: Khalid Mahmood, Wayne David, Ian Lucas, Mark Tami, Chris Mole, David Wright and Iain Wright.

[21] During the debate on The Queen's Speech on 15 November, Blair said Conservative leader David Cameron was a "flyweight against a heavyweight" at the next general election, widely interpreted as implicit support for Brown.

[22] In January 2007, Brown outlined a number of his potential policies for Britain, mentioning citizen responsibility, education, efforts to solve problems in Africa and "a new style of politics" as his priorities.

[27] On 17 January, left-wing MP John McDonnell claimed that support for his leadership challenge had grown to within striking distance of the necessary backing.

Michael Meacher, former Minister of State for the Environment in the DETR and its successor Defra announced that he was also seeking nominations from MPs and was considering standing.

[28] On 22 February he became the third Labour MP to announce his intention to stand for the leadership, although critics in the media expressed doubt over the extent of backbench support for either challenger at this point.

Labour faced mixed results, making gains in some areas, with slightly higher support than the previous year in the Local Elections and fairly minimal losses in the devolved elections, remaining the largest party in Wales and having one less seat than the SNP in Scotland, while losing many English council seats, mainly to the Conservative Party.

Blair ignored Cameron's taunts regarding the possible chaos caused by interim arrangements for election of a new Labour leader and the upcoming resignation of John Reid from the government.

[48] On 10 May, John McDonnell and Michael Meacher delayed a decision over which one should run, describing their respective levels of support as "too close to call".

Jon Cruddas named the issue of insecurity at work; Hilary Benn said that more housing was needed; Peter Hain described inequality as "the biggest challenge we face as a government"; Alan Johnson focused on social mobility; Hazel Blears mentioned education and employment opportunities; Harriet Harman said that Labour needed to "win back the trust and the confidence of the British people" and emphasised the importance of policy implementation.

Hilary Benn was critical of Bob Geldof and defended the settlement of the recent G8 Summit in Germany, while Hazel Blears focused on anti-social behaviour.

Peter Hain accused Home Secretary John Reid of "fanning up" the previous week's debate over possible introduction of new stop and search powers for police, saying "I don't believe in macho posturing on law and order and terrorism".

Brown was declared Leader of the Labour Party at a special conference on 24 June 2007, while in an election on the Alternative Vote system, Harriet Harman won the Deputy Leadership by 50.4% to Alan Johnson's 49.6% after preferences were re-distributed, Jon Cruddas coming narrowly third.

During the months leading up to Tony Blair's resignation, media attention focused on a wide range of Labour politicians, most of whom publicly refused to stand: Tony Blair tendered his resignation as Prime Minister of the United Kingdom after ten years, to Queen Elizabeth II on 27 June 2007 and Chancellor of the Exchequer, Gordon Brown was asked by The Queen to form a new government.