GOV.UK lists Jarvis as the current defence secretary and says he was appointed on 11 June 2026. The same official profile says he had previously served as a minister of state at the Home Office and at the Cabinet Office until the day of the appointment.
The appointment followed Healey's resignation earlier on 11 June. AP reported that Healey quit after saying the government was unwilling to spend enough on the military at a time of rising threats. ITV also reported that Jarvis was appointed after Healey's resignation and identified the dispute as one over military funding.
The Guardian reported that Healey resigned after criticism of Prime Minister Keir Starmer's defence plan. It said Healey argued the plan did not provide the resources he believed were needed, while Starmer's position was that defence spending had to rise in a way consistent with public finances.
The dispute centres on the Defence Investment Plan, the government's planned programme for military funding and capability. In plain terms, a defence investment plan sets out what the government expects to spend, when that money is available and which military capabilities it intends to fund. The political conflict is not only over the headline level of spending, but over whether the timing and scale of the plan match the threats ministers say the UK faces.
AP reported that Starmer responded to Healey by saying the funding plan would provide sustainable and fair increases while keeping the UK safe. That is the government's counter-position: it does not reject higher defence spending, but argues that the increase has to be balanced against other fiscal commitments.
The Guardian reported that the argument included pressure over future defence spending as a share of gross domestic product, the measure that compares military spending with the size of the economy. It said Healey wanted a stronger commitment than the plan offered, while Starmer and the Treasury were resisting a larger near-term settlement.
Jarvis enters the post with a biography that is unusually relevant to the department he now leads. GOV.UK and ITV identify him as a former minister; ITV reported that he is also a former army officer. Those facts do not settle the policy dispute he inherits, but they explain why his appointment was immediately framed around defence credibility rather than ordinary cabinet management.