Sir Olly Robbins to face MPs over Mandelson vetting amid Starmer pressure

Sir Olly Robbins is set to appear before MPs over the vetting clearance granted to Peter Mandelson. The market on Prime Minister Keir Starmer leaving office by December 31, 2026, sits at 64.5% YES.

The scandal has added pressure on Starmer. The June 30, 2026 market is at 36.0% YES, flat over the past day but up from 18% a week ago. Traders appear to be pricing in potential catalysts before June. The December 31, 2026 market has been more active, with a 15-point rise over the last seven days, pointing to stronger expectations of a departure in the second half of the year.

The June 30 sub-market trades $39,539 in face value daily, with $14,185 in actual USDC. It would take $3,372 to shift the odds by 5 points, which indicates moderate liquidity. The December 31 market moves $20,317 in face value and $13,367 in actual USDC, with similar depth. A recent 2-point spike points to active trading interest.

Opposition criticism and internal Labour dissent are both growing, and traders are pricing in the risk of accelerated leadership challenges. At 36¢, a YES share pays $1 if Starmer exits by June 30, a 2.78x return. For that bet to pay, a significant shift would need to happen within the next 71 days.

Watch for what comes out of Robbins’ committee appearance and any movement within Labour’s internal ranks. Either could trigger further volatility in Starmer’s market odds.

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