Under the UK’s grotesque electoral system, a national breakthrough by a small party is more or less impossible. But in the new constituency of Bristol Central, the Green Party leader Carla Denyer is running Labour’s Thangam Debbonaire very close in the polls. Accounts of the race in the national press often recreate stereotypes of Bristol being somehow alternative, ‘bohemian’, quirky, as if voting Green were a bourgeois eccentricity reserved for people who play lyres and wear purple shirts. But the Green wave in Bristol has been a long time coming, and has its roots in disaffection with the way the city has been run at a local level. It also tells us something instructive about Labour in power, which may prefigure what happens when Keir Starmer takes over as prime minister in July.

In May 2012 Bristol voted narrowly to have a directly elected mayor, and six months later an independent candidate, the architect George Ferguson, was voted in, beating Labour’s Marvin Rees. It was a humiliating defeat, and rare in a city the size of Bristol. Ferguson had no real funding and little organisational backing, while Rees had the Labour Party machine behind him. Under the mayoral system, the mayor forms a cabinet which holds most of the power while councillors are more or less lame ducks. Ferguson included other parties in his cabinet. He struggled with the historic levels of underinvestment in the city; parking charges made him unpopular with some residents. Taxi drivers used to rant about Ferguson and his trademark red trousers.

Bristol was one of the centres of Corbynism after 2015. Labour Party membership jumped massively. In one branch in South Bristol, the number went from a hundred to over seven hundred in a few months. But the levers of party power remained embedded in the old structures, especially when it came to the selection of candidates. Attempts to challenge some of the more centrist Labour MPs came to nothing.

Rees stood for mayor again in 2016 and won handsomely, with Labour also taking 37 council seats out of 70. It was a historic moment with Rees becoming the city’s first black mayor. Corbyn came to Bristol to celebrate one of Labour’s rare victories in that year’s local elections, although Rees’s politics were a long way to Corbyn’s right.

One of Ferguson’s flagship policies had been to prepare the way for an arena for musical and other events, to be built on a derelict site near Temple Meads station. But Rees cancelled the plan in 2018, despite its having the support of a majority of councillors, including a number in the Labour Party. The arena project was moved out to Filton, an area with poor transport links, difficult to reach from the central station. It remains a long way from being open. On the city centre site meanwhile, two office blocks, 550 flats, a hotel and conference centre are now springing up. Known as ‘Temple Island’, the project is managed by Legal & General. In an extraordinary part of the deal Bristol Council agreed to underwrite the rent on the offices for forty years, guaranteeing L&G income from the public purse even if the space remains unoccupied.

Another controversial development, pushed forward by Rees and his cabinet, was something called the ‘Western Harbour’ project (a name not used by anyone who actually lives there). It was sold as a replacement for a decrepit road system connecting north and south Bristol, but also envisages large numbers of houses partly in a flood zone, and threatens an area of green belt, woodland, water habitats and parkland used daily by many Bristolians.

Rees was not dealt an easy hand: like other municipal leaders he had to deal with savage central government cuts as well as Covid, and unlike other councils Bristol did not go bankrupt. But by the local elections of 2021, many of those who had joined Labour after 2015 had left: some joined the Greens; others went into environmental activism. Rees was re-elected as mayor but his majority in the council was gone. The Greens and Labour each won 24 seats. Yet Rees set up a Labour-only cabinet, where real power was exercised. A series of bitter rows erupted over housing developments, including the seemingly unfettered construction of student flats with little concern for the environment or infrastructural investment, amid the usual crises over schools, GPs and dentists (a huge queue for a new dentist in Bristol earlier this year made national headlines).

In 2022 there was another referendum on the mayoral system, called by councillors. Labour’s campaign in favour of keeping it was barely perceptible, and largely based on complaints about the costs of the referendum itself (when Ferguson was in power the party had complained that the mayoralty was ‘autocratic’). Perhaps they thought nobody was interested. But in a surprise result, Bristol chose to abolish the mayoral system, by 59 per cent to 41 per cent on a 28 per cent turnout. Rees – in no small part thanks to the way he had run his exclusive cabinet – would be the last directly elected mayor of Bristol.

In last month’s local elections, which brought Rees’s second term to a close, the Greens came near to an overall majority, taking more Labour seats. They now have 34, while Labour have slumped to 20. Against all expectations, Rees failed to be selected as Labour’s parliamentary candidate in the new constituency of Bristol North East. The Greens topped the local polls in all seven wards in the new Bristol Central constituency, including Clifton Down, where Denyer was a councillor from 2016 until stepping down last month to run for parliament.

Bristol is a deeply divided city, socially, ethnically and culturally. The leafy villas of Clifton look down on much poorer zones below, with areas marked by extreme poverty, drug use and homelessness. On the outskirts, traditionally Labour heartlands, disaffection with politics is almost total. In the working-class suburb of Hartcliffe – where 66 per cent backed Brexit in 2016, bucking the trend in the city as a whole – only 14 per cent turned out to vote in the latest council elections (all three seats were held by Labour). Democracy has become almost completely irrelevant there. It’s part of Bristol South, where polls show Labour’s Karin Smyth easily holding her seat.