Part of the problem for the government is that the fallout from the cutbacks has coincided with the Group of 7 summit, where Britain is eager to showcase its role as a leader and convener of countries. Some of the groups most heavily affected by the cuts are active in issues that Britain is highlighting in Cornwall.
Britain, for example, has contributed 15 million pounds, or $21 million, a year to UNAIDS, the United Nations program on H.I.V. and AIDS, for the last five years. Now it plans to cut that by 80 percent, to 2.5 million pounds, or $3.5 million, even as Mr. Johnson has made the pandemic and health security a centerpiece of the summit meeting.
“The decision was controversial to begin with,” said Simon Fraser, a former top civil servant at the Foreign and Commonwealth Office, speaking of the broader budget cuts. “What is more controversial is how it has been implemented. The real-life consequences of it are just coming to the fore, and the timing is terrible for the government.”
Government officials insist they will revisit the budget cuts next year. But Mr. Fraser and others predict the Treasury will balk at reversing them quickly, given the continued heavy spending on pandemic relief. The government is still subsidizing wages for tens of thousands of people who lost their jobs.
Officials point out that Britain took the lead in setting up initiatives like Covax, which aims to provide equal access to Covid vaccines. AstraZeneca, the Cambridge-based drugmaker that manufactures a vaccine developed by the University of Oxford, was the first to join Covax and provides the bulk of its supply.
Critics hope President Biden will press Mr. Johnson to restore Britain’s aid spending, even if the American record on aid is itself mixed. A group of Democrats in the House of Representatives, led by Representative Joaquin Castro of Texas, sent Mr. Biden a letter Sunday, appealing to him to raise the issue with Mr. Johnson when the two meet in Cornwall on Thursday.
“It is absolutely essential that Biden looks Boris in the eye and says, ‘We need you to come back,’” Mr. Drummond said.