[8] In 2012, selected by an individual ballot of Labour Party members in the city to stand for Mayor of Bristol, Rees defeated four other candidates for the nomination, including the Leader and Deputy Leader of the Bristol City Council Labour group and a former Member of Parliament, Dan Norris, who would later become Mayor of the West of England.

In August 2016, Rees instigated a voluntary severance programme aimed at reducing the size of the council's workforce from 6,970 by 1,000.

[22][24] The council housing manager stated the missed target was delay rather than failure, with at least 1,028 affordable homes expected from current projects in 2022/23.

[29] The main reasons Rees gave for his decision were building cost, financial risk, and job creation.

Costs arising should the arena not be successful would fall on the council, and expert advice was that the venue size was too small for major events.

[30] The decision was also heavily influenced by an agreement to secure a 17,000-seat arena in the north of the city, built with private investment at no public cost.

Rees argued he had made a choice to expend his political capital on employment, housing, education, and tackling racism rather than a contentious symbolic matter.

The mayoral election took place in May 2021, and Rees was re-elected with 56.5% of the votes in a second round against the Green Party candidate, who won 43.5%.

[41] However, under the Mayoral model Rees was able to continue to exercise executive control of the council through a cabinet of exclusively Labour councillors.

[42][43] In October 2020, Rees was awarded an honorary fellowship by the Royal Institute of British Architects for his work as a "city maker".

In May 2022, a referendum took place in Bristol to decide if the city should continue being run by a mayor or a council-led committee system.

[46] In June 2022 Rees was criticised for taking a 9,200-mile (14,800 km) flight to Vancouver to speak about climate change at a TED event.

Shortly afterwards it was reported that LDRS staff would not be allowed to attend the mayor's future press conferences, resulting in a boycott of those events by several local news outlets, as well as the BBC and ITV.

[51][52] In 2023 he sought selection as the Labour prospective parliamentary candidate for the new seat of Bristol North East at the 2024 general election.

[55] His nomination was accompanied by commendations from local councillors and MPs but received a significant number of criticisms published on the dedicated web pages.

[9][63][64] According to Rees, his paternal four-times-great-grandfather was executed by the colonial Jamaican government for participating in the 1865 Morant Bay rebellion.

The documentary was made by Uplands TV and had full behind the scenes access to Mayor Rees and his senior team.

[64] Rees was appointed Officer of the Order of the British Empire (OBE) in the 2024 New Year Honours for services to local government.