Cutting UK funding for a highly effective vaccination programme could lead to the deaths of hundreds of thousands of children in some of the world’s poorest countries, aid agencies have warned.

Data from the Global Alliance for Vaccines and Immunisation (Gavi), a major recipient of UK aid, indicates that even a slight reduction in funding would significantly decrease the number of vaccinations administered, resulting in a large number of preventable deaths.

According to projections based on Gavi’s records and seen by The Guardian, any reduction in the UK’s contributions could intensify pressure on the government, which is already facing criticism for redirecting overseas aid towards defence spending. The backlash follows the recent resignation of international development minister Anneliese Dodds in protest against the cuts.

Meanwhile, the head of the British Council, which partly relies on the aid budget, has urged ministers to preserve the UK’s global influence through cultural and diplomatic initiatives.

Previous calculations suggested that maintaining UK funding at its current level—rather than increasing it by 10% as originally expected—would mean 8 million fewer children receiving vaccinations, leading to approximately 200,000 preventable deaths. With the UK’s overall aid budget set to drop by 40%, aid organisations fear an even higher death toll if Gavi’s funding is cut proportionally.

The Foreign Office has stated that decisions on specific aid programmes will not be made until the upcoming spending review. However, aid officials are bracing for major reductions, despite Prime Minister Keir Starmer’s commitment to prioritising vaccination efforts and humanitarian relief in crisis zones such as Sudan and Gaza.

Although the UK’s aid budget is set to decline from 0.5% of gross national income to 0.3% by 2027, analysts warn that once domestic spending—such as housing asylum seekers—is accounted for, the actual overseas aid budget could shrink to just 0.23%, the lowest recorded level.

These cuts are particularly concerning in light of previous reductions in global vaccination funding, including the effective suspension of USAid’s immunisation programmes under former US President Donald Trump.

The UK has contributed over £2bn to Gavi in the past four years, alongside key donors such as the US government and the Bill & Melinda Gates Foundation. Aid groups argue that Gavi’s work is highly cost-effective, with the alliance having vaccinated more than 1.1 billion children in 78 countries over the past 25 years, preventing nearly 18 million deaths.

An aid agency representative warned that slashing UK support for Gavi would be an easy financial decision but would come at a devastating human cost.

A spokesperson for Gavi expressed optimism about Starmer’s recognition of vaccination as a funding priority.

They added: “While we appreciate the competing priorities every country is faced with, any cut to UK funding would have a disastrous effect on Gavi’s work supporting routine immunisation of more than half the world’s children, maintaining global stockpiles of vaccines against diseases like Ebola and cholera, reaching vulnerable communities in humanitarian contexts with vital services, and helping countries and the world quickly respond to outbreaks.”

The spokesperson warned that such cuts would "undo years of progress, weaken global security in the face of future crises, and hinder countries' efforts toward self-sufficiency."

The British Council is also at risk, having cautioned last month that potential budget reductions of £250m could force it to withdraw from up to 40 countries. This financial strain stems from commercial interest rates applied to government-issued Covid-era loans.

Scott McDonald, the British Council’s chief executive, acknowledged the need for defence spending but stressed the importance of maintaining international alliances and influence through soft power initiatives. He highlighted the Council’s track record in countering disinformation, promoting media literacy, and fostering social cohesion, all of which contribute to the UK’s security objectives.

He further emphasized that it is "crucial that aid budget cuts are not implemented in a way that harms the UK’s reputation and global influence."