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- The Green Party have shortened considerably in the betting for the Holborn and St Pancras by-election, with bet365 now pricing them at 2/1 behind Labour's 4/11.
- Green Party leader Zack Polanski announced his intention to stand in the by-election earlier this week
- The by-election was triggered by former prime minister Sir Keir Starmer's resignation from the House of Commons on 1 September 2026
Green Party Shorten As Polanski Eyes Seat
The Green Party have shortened considerably in the betting for the Holborn and St Pancras by-election, with UK betting sites reacting to news that party leader Zack Polanski intends to stand in the constituency once held by former prime minister Sir Keir Starmer.
bet365 now has the Greens at 2/1, comfortably the clearest challenger to Labour's 4/11 favouritism in what's shaping up to be a genuinely high-profile contest.
Polanski announced his intention to stand on 3 September, following a period of speculation about his plans, though his candidacy isn't yet fully confirmed since it still requires formal nomination from local Green Party members.
Should that nomination go through, it would set up a high-stakes contest for the left of British politics in a seat with obvious symbolic weight given its previous occupant.
Notably, Polanski has said he'll remain as Green Party leader regardless of the by-election's outcome, a statement that removes some of the risk typically associated with a party leader contesting a seat they might not ultimately win.
Labour Favourites As Green Party Close In
With seven parties currently priced up, Labour remain clear favourites to hold the seat, though the Green Party's shortening price is the standout story of the market so far.
| Holborn And St Pancras By-Election | Odds | Implied Probability |
|---|---|---|
| Labour | 4/11 | 73.3% |
| Green Party | 2/1 | 33.3% |
| Reform UK | 100/1 | 1.0% |
| Workers Party of Britain | 150/1 | 0.7% |
| Lib Dems | 200/1 | 0.5% |
| Conservatives | 250/1 | 0.4% |
| Restore Britain | 250/1 | 0.4% |
Labour's implied probability of 73.3% still makes them the clear favourites to hold this traditionally safe seat, but the Green Party's 33.3% represents a genuinely significant chunk of market confidence for a challenger in what's historically been considered Labour territory.
That gap between first and second is worth watching closely as Polanski's candidacy moves toward formal confirmation.
The Seat Behind The Contest
A by-election for the Holborn and St Pancras constituency in London is due to be held at some point in 2026, following Sir Keir Starmer's resignation from the House of Commons on 1 September 2026.
The seat's profile as Starmer's former constituency ensures this will be one of the more closely watched by-elections in recent memory, regardless of when it's eventually held.
Contests of this kind often attract outsized attention precisely because of who previously held the seat, and Holborn and St Pancras is unlikely to be any different given the significance of Starmer's own political journey.
By-elections in seats vacated by such high-profile figures have a tendency to draw national media attention far beyond what the local result alone would normally command.
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Where To Bet On The Holborn And St Pancras By-Election
For those looking to get involved in the market, bet365 is offering prices on all seven parties, and you can find out more via the bet365 review on OLBG.
With a specific date for the by-election still to be confirmed, this looks like a market well worth following closely as Polanski's candidacy moves toward formal nomination.
Checking out some of the top political betting sites is a sensible starting point for anyone newer to by-election markets.
