Here are the runners and riders to replace John Healey as defence secretary following his shock resignationJohn Healey’s resignation is the beginning of the end for StarmerDouglas Alexander – The Scotland secretary is an experienced politician and former Labour government minister. He currently holds a cabinet position and previously served as a trade minister, with known ambitions beyond his current role, Alexander considered a safe pair of hands. Al Carns – The current Armed Forces minister, Carns is a former Royal Marine who completed five tours in Afghanistan and was awarded the Military Cross for gallantry. He is regarded as an 'action man' following his ascent of Everest last year to raise over £1m for military charities, making him a popular candidate among Labour MPs for the role. Dan Jarvis – The security minister, a former member of the Parachute Regiment who served in the Balkans, Afghanistan and Iraq, is characterised as mild-mannered, deeply serious and ultra-dependable. Jarvis was considered a potential Labour leader and challenger to Jeremy Corbyn, but has maintained a relatively low profile in his current role. Luke Pollard – A Plymouth MP and minister in the Ministry of Defence, who is the son of a former Royal Navy submariner, Pollard has been responsible for defence readiness and industry since last September, bringing a strong understanding of defence issues to his role. Heidi Alexander – Transport secretary Heidi Alexander, who re-entered Parliament in 2024 after a period as Deputy Mayor of London for transport, is now serving her second term in the Commons – having previously established a reputation as a highly capable politician during her first tenure as MP for Lewisham. In fullWho could replace John Healey as defence secretary?