The Green Party and Liberal Democrats have formed a joint administration to lead Southwark Council, ending 16 years of continuous Labour majority control. The new administration, which took office on 28 May 2026, commands a majority of 34 seats across the 63-seat council.
The New Political Landscape
The arrangement follows local elections held on 7 May 2026, which resulted in no single party holding overall control. Labour remained the largest party with 29 councillors, but the Greens secured 22 seats and the Liberal Democrats won 12, enabling them to combine for a working majority.
The election saw turnout rise to 40.38 per cent, up six percentage points from the 2022 polls. Votes were counted on 8 May at the Lighthouse Theatre in Camberwell.
The result marks a dramatic shift in Southwark's political composition. After the 2022 election, Labour held 52 seats compared with 11 Liberal Democrats and no Greens. A series of defections changed the landscape: Councillor Kath Whittam joined the Green Party in November 2025, followed by Councillor Sam Foster in December 2025, Councillor Reginald Popoola in January 2026, and Councillor James McAsh in February 2026.
Executive Leadership Appointments
At the Annual Council Assembly on 28 May 2026, Councillor James McAsh of the Green Party was elected Leader of the Council. Councillor Victor Chamberlain of the Liberal Democrats was appointed Deputy Leader.
Councillor Claire Sheppard of the Green Party was elected Mayor of Southwark for the 2026–27 municipal year.
The executive includes dedicated portfolios for key priorities: Councillor Popoola serves as Executive Member for Council Homes; Councillor Sam Foster as Executive Member for Finance and General Purposes; Councillor Eloise Waldon-Day as Executive Member for Climate and Council Coordination; and Councillor Vanessa Threadgold as Executive Member for Parks and Leisure.
Stated Policy Priorities
The Joint Administration has outlined a programme focused on affordability, environmental action, and housing. The coalition has committed to minimising council tax for low-income households and investing in insulation and renewable energy.
On housing, the administration has pledged to build more council homes, address disrepair and damp, and require greater affordable housing provision in new developments. The executive structure reflects this priority through the dedicated Council Homes portfolio.
The coalition has also promised to tackle crime prevention, reduce litter and fly-tipping, and promote green transport. These measures are framed within a broader commitment to making the council more accessible and giving residents greater control over local decisions.
Financial Challenges Ahead
The new administration faces significant fiscal pressures. According to council statements, Southwark is projected to face a funding gap of £85 million due to Government funding reductions.
In the official announcement, Councillor McAsh said: "Southwark residents voted for change and our Joint Administration will bring this to local people. We will work together to make our borough more affordable and greener and we'll stand up together for our borough over the Government's funding cuts, which are set to leave Southwark with a funding gap of £85 million."
Councillor Chamberlain added: "We're thrilled to be working together to put Southwark's residents first and bring change for the people of our borough. We will work in partnership to fix housing, make our streets cleaner and safer, and to ensure the council listens and delivers for local people."
Context and Opposition
Labour, now with 29 councillors, forms the council Opposition. The party had been in continuous majority control since 2010.
The transition follows a notable planning decision earlier in May, when the Planning Inspectorate dismissed an appeal by Berkeley Homes for the Aylesham Centre development in Peckham. The proposed scheme would have delivered 867 homes, including 77 affordable units, but the inspector ruled that the benefits did not outweigh harm to designated heritage assets.
Councillor Sarah King, who served as Labour Leader from 9 July 2025 until the administration change, had supported the council's opposition to the scheme. She described the dismissal as "a great day for Peckham" and thanked the community for their engagement.
What Happens Next
The Joint Administration will now begin implementing its policy programme whilst managing the projected budget shortfall. The coalition's ability to deliver on its priorities for housing, climate action, and affordability will be tested against these financial constraints.
The arrangement represents the first Green–Liberal Democrat coalition in Southwark's history and reflects broader trends of Green Party gains in inner London boroughs.