Wandsworth’s deputy Labour leader is standing down, sparking what could be the most consequential by-election in living memory. At stake: control of Wandsworth Council, and the next four years of power.
Lizzy Dobres holds one of Trinity’s two seats, a knife-edge ward in the borough’s Tooting corner. Her exit landed on the same day that the council’s Conservative leader, Aled Richards-Jones, announced he was quitting after just 44 days, blaming the competing demands of the role and his job as a law-firm partner.
Dobres is said to be going for a similar reason: a move to a politically restricted role that means she can no longer serve. If she goes, Trinity could be back at the polls within weeks, most likely mid-August.
The Conservatives run Wandsworth, but only just, with 29 seats to Labour’s 28. They can only govern through an agreement with independent councillor Malcolm Grimston. If they win Dobres’s seat, which only requires a small swing, it will provide an outright majority and the agreement becomes unnecessary. And that doesn’t account for the Greens, who will throw everything at Trinity in the hope of winning their first Wandsworth councillor.
In return for Grimston’s backing, the Conservatives handed Labour powers it may otherwise have lost in opposition: the chairs of three scrutiny committees, a guaranteed share of committee seats, and the right to speak at Cabinet. Labour keeps all of it only while the Conservatives stay a seat short.
So when would Trinity vote? Labour has not formally confirmed the resignation, and the council has yet to declare the seat vacant. Once a councillor resigns in writing, the seat falls empty, the council posts a notice of vacancy, and two local electors can call a by-election, with the poll following within 35 working days. As a rough guide, if Dobres resigned on Monday, Trinity would most likely vote in mid-August, the result declared that night.
A deal built to end the moment this happens
The signed agreement, between the Conservative group and Grimston, contains a section headed "By-elections". If a by-election changes the make-up of the council "materially", it says, either side may "withdraw from the terms of this agreement". Both parties, in other words, put their names to a deal designed to come apart the instant a vote like this shifts the balance. The Conservatives would be the ones with reason to trigger it: a majority removes their need for the arrangement at a stroke.
Grimston's leverage rests on a rule that any change to the council's constitution, its rulebook, needs the backing of either two political groups or one group plus an independent. That is his effective veto, and it holds only while no single party has a majority. Labour's committee chairs and its guaranteed share of seats rest on the same arithmetic.
On 22 July, under the terms of the Grimston deal, the council is due to pass its rewritten rulebook, and the Conservatives expect to choose Richards-Jones's successor as leader at the same meeting. Richards-Jones stays on as a ward councillor, so his exit changes nothing in the arithmetic; Dobres's seat is another matter. That single meeting could bring a new leader, a new constitution and next April's council-tax plans, even as a by-election looms that could pull the balance out from under it all.
A three-way race the Greens could decide
Across Wandsworth in May, the Green share of the vote more than doubled, from 7.6 to 17.3 per cent. In Trinity itself the Greens took about 14 per cent, up from under 5 four years earlier. And in the neighbouring ward of Tooting Broadway, they came within 51 votes of their first-ever Wandsworth councillor.
That surge is what cost Labour the borough, on the account of Labour's own leader. In a video posted after the election, Simon Hogg said: "Our fears that a split in the votes between Labour and Green would let the Tories in have come true." More than half the votes cast in Wandsworth, he noted, went to Labour or the Greens, and the borough got a Conservative council anyway. The numbers bear him out: the Conservatives gained seats across the borough even as their own share of the vote fell, winning on a divided opposition rather than a surge of their own.
In a by-election that arithmetic matters more, not less. A standalone by-election here tends to draw well under half the turnout of a full council election, and a ward divided three ways on a smaller vote is hard to call: a modest change in where the Green vote settles could hold the seat for Labour or hand it to the Conservatives. The Greens, having come so close next door, will fight to take it outright. One of two things seems certain: they will either win, or determine the winner.
Four years ago Trinity was a comfortable Labour hold, both seats red. In 2026 it split one seat each, the second decided by just 64 votes. A seat that was safe has become a coin-toss, and it now carries the balance of the borough.
