**Sagal Abdi-Wali leads the market at 64% as the clear frontrunner for Labour’s nomination in the Holborn and St Pancras by-election, triggered by Sir Keir Starmer’s resignation on 1 September 2026.** Labour has held the seat continuously since 1983, most recently with a 30-point majority in 2024, and the party’s local dominance in Camden underpins trader expectations of another hold once the candidate is confirmed on 9 September. Abdi-Wali, Camden Council leader and former constituency party chair, benefits from strong local ties and recent momentum after winning the council leadership in May following Green gains in the local elections. Zack Polanski’s announcement on 3 September that he will contest for the Greens has lifted his price to 25%, reflecting the party’s improved local showing (second place in the 2026 Camden vote share) and a potential challenge in a seat where Greens took 10.4% in 2024. Lower-priced names such as David Stansell (7%), Pat Callaghan (5.4%), and others remain long shots pending full candidate lists from other parties. The by-election writ timing and final nominations will determine whether the current pricing holds, with Labour’s structural advantage the dominant factor in current trader consensus.