The UK has pledged $1.6bn since 1985 in efforts to fight polio, according to Devex.
A spokesperson for FCDO said: “The UK is a world leader on international development. In 2020 we were the third biggest aid donor globally, spending £14.5 billion.
“The seismic impact of the pandemic on the UK economy has forced us to take tough but necessary decisions, including temporarily reducing the overall amount we spend on aid. We will still spend more than £10 billion this year to fight poverty, tackle climate change and improve global health.
“We are working through what this means for individual programmes. Decisions will be announced in due course.”
The cut in funding comes as the international campaign to eradicate polio is finding it frustratingly hard to stamp out the disease in its remaining haunts.
Pakistan and neighbouring Afghanistan are the only two remaining nations where the poliovirus is still endemic. Yet efforts have stalled amid violence, suspicion of vaccines and mismanagement.
Disruption from the Covid-19 pandemic has further hampered campaigns.
Pakistan last year saw both stubbornly high numbers of wild poliovirus and growing incidences of new vaccine-derived strains. The country recorded a total of 167 cases in 2020, up from only 12 two years earlier.
Conspiracy theories and fake health scares have left a section of parents unwilling to get their children vaccinated.
In Afghanistan, millions of children have gone unreached after the Taliban banned door-to-door vaccination campaigns in territory they control. The insurgents have accused health workers of acting as spies for drone strikes and special forces raids.
The edict has created a large pool of vulnerable, unvaccinated children where the virus could run riot.
Attempts to negotiate with the Taliban to regain access have so far failed. The militants will only agree to allow vaccinators to give out drops at central points such as village mosques, but epidemiologists say that is not enough to reach everyone.
Protect yourself and your family by learning more about Global Health Security