Since 2025 the UK has rebuilt ties with the EU through sectoral deals on food, carbon, fishing and defence — without rejoining. Keir Starmer's resignation now tests the 'reset', with direct stakes for Luxembourg.
Keir Starmer announced his resignation as UK prime minister on 22 June, triggering a Labour leadership contest that Andy Burnham is favoured to win — and casting doubt over a planned UK-EU summit that matters to Luxembourg.
British Prime Minister Keir Starmer announced on 22 June 2026 that he will resign as Labour leader, bowing to a party revolt less than two years after a landslide win. He will stay on as caretaker until a successor is chosen, with nominations opening on 9 July and a new prime minister expected by September. The trigger was rival Andy Burnham's by-election return to Parliament; the change reshuffles a key EU partner at a sensitive moment for Ukraine policy.