Prime Minister Sir Keir Starmer is poised to approve an £18 billion increase in the United Kingdom’s defence budget, a move aimed at modernising the armed forces amid ongoing global tensions and to bolster his position within the government. The announcement is expected as early as next week, following months of delays and debate within the Treasury over the scale and affordability of the proposed boost.

Senior defence officials have emphasized that the additional funding is crucial for equipping the military with advanced technology, jets, and munitions needed to confront future conflicts. Jonathan Powell, the national security adviser, recently cautioned Starmer in a letter that without such an increase, Britain risks losing its influence on the global stage. Powell noted that allied nations have committed to significantly higher defence spending, underscoring the danger posed by Britain’s comparatively restrained budget.

The precise mechanism for financing the increased expenditure remains unclear, though a Whitehall source has indicated the government considers the expansion “fully affordable.” The prime minister has previously pledged to prioritise defence and security throughout his tenure, particularly in light of persistent conflicts in Ukraine and Iran. He has also expressed an ambition to raise defence spending to 3 percent of GDP during the next parliamentary term. Critics argue that failing to meet these targets would undermine those commitments.

The proposed surge in defence investment comes amid wider political turbulence. Six Cabinet ministers reportedly support Labour politician Andy Burnham’s candidacy in the upcoming Makerfield by-election, scheduled for June 18, hoping he could unseat Reform UK and potentially challenge Starmer’s leadership. Burnham has received endorsement from six members of Labour’s national executive committee to stand in the election.

Meanwhile, government borrowing costs have climbed to their highest level since 1998, driven in part by investor concerns that Burnham might increase public spending and loosen fiscal constraints if he returns to Westminster. Adding to the pressure on Starmer, former U.S. President Donald Trump renewed his criticism of the prime minister, specifically targeting Starmer’s policies on migration and offshore wind power, and expressed skepticism about his political future.

With these internal and external pressures mounting, Cabinet colleagues expect Starmer’s defence spending announcement to serve both as a reaffirmation of his leadership and a strategic response to growing challenges on multiple fronts.