British Defense Secretary John Healey resigned Thursday over the government’s planned defense spending, which he said could weaken national security.

In his resignation letter to Prime Minister Keir Starmer, Healey said the government’s Defence Investment Plan (DIP) fell “short of what is required at this dangerous time.” 

My letter to the Prime Minister pic.twitter.com/j9z9nmLCb1

— John Healey (@JohnHealey_MP) June 11, 2026

Quoting Starmer’s own words, Healey said the United Kingdom could face a Russian attack on NATO members as early as 2030. He warned that without an investment plan matching the level of threat, he would be forced, as defense secretary, to make decisions that would “increase risk to personnel” and “could make the country less safe.”

“After explaining to you that I would not be able to accept a DIP settlement that does not give our forces the resources they need, I am now left with no other option than to submit my resignation as your defense secretary,” Healey further said. 

His departure comes amid growing political tension in London over defense spending and the long-delayed publication of the DIP, which has reportedly been held up by disputes between the Ministry of Defence and the Treasury.

Hours after Healey’s resignation, junior defense minister Al Carns also stepped down, saying he could not defend “a level of investment I know to be inadequate to the task.”

Prime Minister Starmer expressed regret over Healey’s resignation but defended the government’s approach, saying the plan would provide “sustainable and fair” spending increases designed to maintain national security.

Later Thursday, Starmer appointed Dan Jarvis, formerly the security minister, as the new defense secretary.