Katie Williams
Live reporter

In his resignation letter, Healey accused the prime minister of failing to commit the resources the military needs.

Let's take a closer look at the government's defence spending commitments, and what Healey has said today:

The government's commitments

In February 2025, the government committed to increase defence spending to 2.5% of GDP by 2027. It also announced a change in the definition of defence spending to put that figure at 2.6%.

As part of that commitment, the government outlined an ambition to reach 3% in the next parliament.

Separately, the UK has committed to a Nato target to spend 5% of GDP on "national security" by 2035.

The government says this would be made up of 3.5% of GDP on "core defence" and another 1.5% of GDP going on things like protecting critical infrastructure and ensuring civil preparedness.

What Healey said today

Healey said today that there are "credible ways of meeting the mid-term funding challenges", but that the financial settlement for the defence investment plan "falls well short of what is required".

He says the extra support in the plan is "backloaded" when he believes the pressure to speed up readiness "is in the first two years".

Healey adds that defence spending "rises to just 2.68% of GDP in 2030". As BBC Verify reports, that implies an 0.08% increase on the existing 2027 commitment.