The highest government office of Hong Kong, the Chief Executive, is selected by a 1,200-member Election Committee (EC) which is divided into various subsectors and dominated by pro-Beijing politicians and tycoons.

[7] Other minor candidates included insurer Jenny Kan Wai-fun, Vincent Lau Chi-wing, barrister Albert Leung Sze-ho,[9] ex-DAB member Wu Sai-chuen[10] and Professor Yu Wing-yin.

Leung Chun-ying, who was expected to seek a second term, also unleashed a thinly-veiled attack on Tsang, suggesting ministers should be "responsible" and focus on the upcoming policy address and budget rather than thinking about joining the race.

[41] On 9 December, two days before the election, Leung surprisingly announced he would not seek re-election, citing his daughter's ill health, which made him the first Chief Executive to serve only one term.

[43] After the election, the two potential candidates, John Tsang and Regina Ip, resigned from their Financial Secretary and Executive Councillor posts on 12 and 15 December respectively, being expected to run.

She called for a relaunch of the electoral reform process under Beijing's restrictive framework as decreed by the National People's Congress Standing Committee (NPCSC) on 31 August 2014.

[48] Lam officially declared her candidacy on the same day, promising good governance with greater transparency and "new blood" in her cabinet, at a press conference in which she was joined by Executive Councillor Bernard Chan, director of her campaign office.

[50] John Tsang officially declared his candidacy on 19 January with a slogan of "Trust, Unity, Hope", after more than a month-long delay in the acceptance of his resignation by the central government, which put his campaign in limbo.

In a closed-door meeting with senior media executives on 20 January, Lam reportedly said she decided to run to prevent the election from being won by someone not accepted by Beijing, which would cause "constitutional crisis".

A similar gaffe followed shortly thereafter when it was reported that Lam did not know convenience stores do not sell toilet paper and had to take a cab back to her former official residence to get one, which was dubbed "loo paper-gate" by English media.

She also revealed a star-studded campaign team, which included a council of chairpersons consisting of Ronald Arculli, Laura Cha, Moses Cheng, Jonathan Choi Koon-sum, Timothy Fok, Lam Tai-fai, Eddy Li Sau-hung, Victor Lo, Lo Man-tuen, Anthony Wu, Yu Kwok-chun and Allan Zeman; senior advisers consisting of heavyweights including senior pro-Beijing politicians including Chan Wing-kee, Cheng Yiu-tong, Hung Chao-hong and Rita Fan, tycoons such as Robin Chan, Aron Harilela, Xu Rongmao, Robert Kuok, Peter Lam, Lee Shau-kee, Vincent Lo, Robert Ng, Peter Woo and Charles Yeung and others such as Lawrence Lau, Lau Chin-shek, Li Fung-ying and Joseph Yam.

[60] On 5 February, Woo Kwok-hing updated his election platform, including the implementation of the Basic Law Article 22, which states that no mainland authorities can interfere in Hong Kong internal affairs.

[61] On the next day, John Tsang unveiled his 75-page election platform entitled "Convergence of Hearts, Proactive Enablement", with the promise of revisiting Article 23 national security legislation and political reform.

His bid was supported by four radical democrat legislators People Power's Raymond Chan, Demosisto's Nathan Law, Lau Siu-lai and Eddie Chu, while the mainstream pro-democrats cast doubt over Leung's candidacy, believing it would contribute to the victory to Carrie Lam.

[63] Being the only one of the four candidates who had not published an election platform, Carrie Lam held a press conference titled "WeConnect: Manifesto Step 2" on 13 February, one day before the nomination period, to reveal some details of her manifesto, including boosting education spending to HK$5 billion, tax cut to small- and medium-sized enterprises, and creating more land for housing through reclamation, urban redevelopment, and developing brownfield sites or country parks.

[73] During the nomination period, it was reported that HKMAO director Wang Guangya told the electors at a meeting in Shenzhen that John Tsang was the contender with the least support from the central government.

Amid the alleged pressure from the Liaison Office which actively lobbied for Carrie Lam, Tsang struggled to seek nominations from the pro-Beijing camp and had to rely heavily on the pro-democrats.

"[95][96][97] In response to controversy surrounding her lack of a full election platform, Lam revealed a manifesto titled "Connecting for Consensus and A Better Future" on 27 February, two days before the nomination period ended.

[119] She was also criticised after one of her campaign staffers said she was "too tired" to make the trip to visit the community in Tin Shui Wai, a New Territories new town with a high proportion of lower-income residents.

"[121] The rally was held after Tsang faced a fresh round of criticism from veteran Beijing loyalist Lo Man-tuen, who was vice-chairman of the Chinese People's Political Consultative Conference’s (CPPCC) subcommittee on foreign affairs and member of Carrie Lam's campaign office.

Lo also wrote that Beijing does not trust Tsang because of his "lack of principle on major issues", namely the Occupy protests and 2016 Mong Kok civil unrest.

He said Tsang failed to join the Chief Executive and other principal officials in a signature campaign organised by the Alliance for Peace and Democracy against the Occupy Central movement that challenged Beijing's authority" and even expressed appreciation for the local film Ten Years, which was considered a smear on "one country, two systems", in addition to his "laid-back" working style.

[121][122] On 24 March, National People's Congress (NPC) chairman Zhang Dejiang and head of the United Front Work Department Sun Chunlan reportedly arrived in Shenzhen to meet with electors from different sectors to lobby for Lam.

Richard Li subsequently endorsed Lam in an interview published in three Chinese-language newspapers – Ming Pao, Hong Kong Economic Journal and Wen Wei Po.

After the announcement of Lam winning with 777 votes, citizens ridiculed the number on social media as the word "seven" in Cantonese, pronounced as tsat, is often used as a vulgar term associated with stupidity.

Many of them mingled and chatted in Mandarin and various dialects, displaying banners bearing the names of the organisers, the residents associations of their mainland home cities, such as Guangzhou, Xiamen and Shanwei.

[135] At the AsiaWorld-Expo, the unused backup polling station, two notebook computers storing the name list of the 1,194 Election Committee members and personal data of all 3.78 million registered voters were reported as lost.

The Registration and Electoral Office (REO) posted letters of apology to all affected voters, stating the personal data was "protected by multiple encryptions" which were "extremely difficult to break through".

[138] One day after the election, the Department of Justice charged nine Occupy protests leaders of public nuisance offences, including the three Occupy Central founders – academics Benny Tai and Chan Kin-man, and Reverend Chu Yiu-ming, legislators Tanya Chan and Shiu Ka-chun, former student leaders Tommy Cheung Sau-yin and Eason Chung Yiu-wah, League of Social Democrats (LSD) vice-chairman Raphael Wong and former legislator Lee Wing-tat.

Asked if the prosecutions would embarrass Chief Executive-elect Lam – who said her top task was to heal the social divide in her victory speech – incumbent Leung Chun-ying reiterated that the decision was independently made by the Department of Justice.