Britain is being urged to pledge billions of dollars to get the fight against malaria, tuberculosis and Aids “back on track” after efforts were ravaged by the Covid-19 pandemic. The UK has historically been one of the main donors to the Global Fund, an international financing organisation aimed at ending the three deadly epidemics by 2030. Now it is warning that, unless donors make an unprecedented total funding pledge of $18bn (£13.25bn) this year, that goal will be missed. “In the face of the catastrophic impact of Covid-19 on the fight against HIV, TB and malaria, the choice is stark: we either increase funding, or we abandon hope of finally defeating these epidemics by 2030,” said Peter Sands, executive director of the Global Fund. In a statement seen by the Guardian, a group of African politicians echoed that warning, stressing that the world faces “a critical moment”. “Covid-19 devastated health systems and crippled the global response to health challenges … What follows now will be decisive in getting progress back on track,” write the seven parliamentarians from the Democratic Republic of the Congo, Kenya, Rwanda and Senegal. “Key donor countries who have played an important role in this historic partnership, such as the US, UK and others, once again have the opportunity to demonstrate leadership with strong funding pledges, which will be met by implementing countries upholding commitments to mobilise their own resources.” Campaigners said the UK government’s decision to cut the aid budget from 0.7% to 0.5% of gross national income has already had an impact on global efforts against HIV, Aids, TB and malaria, contributing to a wider stalling of progress during the pandemic. Doubt was cast on Britain’s likely commitment to the Global Fund on Tuesday when the foreign secretary, Liz Truss, said, in a written statement, she was “rebalancing the aid budget towards bilateral programmes” and, implicitly, away from multilateral organisations. The Global Fund said the record target of $18bn was needed because “significant progress” in tackling the three diseases had been lost. “Hard-won gains against HIV, TB and malaria are being reversed, with devastating consequences for the poorest and most vulnerable communities,” it said. “The entire United Nations sustainable development goals agenda is now at risk, as inequities deepen, poverty spirals and social and political tensions grow.” If the target was reached, it said, it would enable the fund to save 20 million lives between 2024 and 2026, and reduce the death toll across the three diseases to 950,000 in 2026, down from 2.4 million in 2020, and from 4 million in 2005. Mike Podmore, director of StopAids, welcomed the African MPs’ call. “These parliamentarians are right to speak out,” he said. “The UK has played a leading role in the global response to date, but in order to avoid losing the substantial progress made against Aids, tuberculosis and malaria, the UK must deliver a strong funding pledge at this year’s replenishment, and maintain its position as the second biggest donor to the Global Fund.” With deaths from TB increasing to 1.5 million in 2020, Aaron Oxley, executive director of non-profit Results UK, said commitment was needed “now more than ever”. “It is essential that the UK government listen to their counterparts in countries who are implementing programmes in partnership with the Global Fund and make an ambitious pledge at the upcoming seventh replenishment.” Gareth Jenkins, director of advocacy at Malaria No More UK, said it was “vital that the UK continues to make a leading down payment on the health security of the world”. According to the World Health Organization, 627,000 people died of malaria in 2020, an increase of 12% on the year before. Most – 96% – were in sub-Saharan Africa. Set up in 2002, the Global Fund raises and spends funds during three-year “replenishment” periods, the seventh of which begins in 2024. The sixth replenishment meeting in 2019 in Lyon, hosted by President Emmanuel Macron, raised $14.02bn, the largest amount ever for a multilateral health organisation. The seventh replenishment meeting will be in the US later this year hosted, by President Joe Biden. A spokesperson for the foreign, commonwealth and development office said: “As one of its largest donors, UK aid to the Global Fund is actively fighting malaria, Aids and tuberculosis around the world. We continue to support the Fund’s vital work.”