What does the pledge mean? 

On 25 February 2025 the Prime Minister Sir Keir Starmer announced the UK will spend 2.5% of its Gross Domestic Product (GDP) on defence from 2027. 

He told MPs: “We will deliver our commitment to spend 2.5% of GDP on defence, but we will bring it forward so that we reach that level in 2027 and we will maintain that for the rest of this Parliament.” 

‘Defence spending’ in this context is broader than just the annual budget of the Ministry of Defence (MOD). The government previously told Full Fact that it refers to all defence spending that falls within the definition of NATO-qualifying spend. This includes some things outside the MOD’s budget, such as armed forces pensions and the Integrated Security Fund, a fund for projects that aim to help tackle threats to the UK’s national security. 

NATO members first agreed in 2006 to spend 2% of their GDP on NATO-qualifying defence, then reaffirmed this commitment in 2014. The UK has met this target consistently, and has exceeded it in recent years, spending 2.3% on defence in each of the last four years.

In April 2024, the then-Conservative government committed to spending 2.5% of GDP on defence by 2030, and Labour’s 2024 election manifesto included a commitment to “set out the path” to reaching 2.5%. 

While Mr Starmer said the 2.5% target would now be achieved “in 2027”, a press release issued the same day said the commitment is “to increase spending on defence to 2.5% of GDP from April 2027”, meaning that spending will reach this proportion in the 2027/28 financial year. 

Sometimes budgets and spending can change over the course of a financial year, so we won’t know definitively if the 2.5% target has been achieved until the end of 2027/28 (unless it is reached in an earlier year). 

The government has also announced that it will update the definition of defence spending “to recognise what our security and intelligence agencies do to boost our security”, and that this will mean that total defence spending from 2027 will be 2.6%. 

It wasn’t immediately clear, however, if this change in the UK’s definition of defence spending correlates with NATO’s definition, and, as such, if the government plans to spend 2.5% or 2.6% of GDP on NATO-qualifying defence in 2027/28. 

When we asked the MOD about this, it told us that more details on the change in definition will be set out in the Spending Review, which is expected in June. But it also said that the new definition is in line with NATO’s definition. 

What progress has been made?

Full details of how exactly the UK will increase defence spending to 2.5% of GDP in 2027/28, from the current level of 2.3%, were not immediately published. 

In his announcement, Mr Starmer said it would be funded by a reduction in Official Development Assistance (ODA, also known as the overseas aid budget) spending from 0.5% of Gross National Income (GNI) to 0.3%. The government told us this would provide £6.1 billion, and Mr Starmer has said this would fully fund the defence spending increase. 

We asked the government if it will be producing a year-by-year plan, such as that published by the last government, and it told us that the Prime Minister had outlined his commitment and any further details would be published “in due course”. 

Without this information, we’re not able to fully monitor the government’s progress towards the 2.5% target year-by-year, so won’t have an indication if the target looks as though it will be met ahead of the pledge’s deadline.