Boris Johnson is being urged to give more COVID-19 vaccines to poorer countries ahead of the G7 summit.
More than 100 cross-party MPs and peers want the prime minister to show “global leadership” and commit to a one in, one out policy when it comes to jabs.
The prime minister is set to chair a gathering of the most economically powerful countries in the world in Cornwall from 11 June.
In the run-up to the summit, the signatories have asked the UK government to donate a dose to the United Nations-backed Covax scheme for every dose bought for use in Britain.
The scheme is providing vaccines to low and middle-income countries.
It comes as the World Health Organisation, the International Monetary Fund, World Bank Group and the World Trade Organisation called for richer countries to give more COVID vaccines to poorer nations in a joint plea across a number of international newspapers.
In a letter, the signatories said there is a “clear moral imperative to act to close the global vaccine divide”, as well as a “rational case… to stop the threat of variants emerging abroad and taking root in the UK”.
It has been backed by senior Tory MPs Peter Bottomley and Dr Dan Poulter – a former health minister who has worked on the frontline during the pandemic.
Others putting their name to the letter include former shadow chancellor John McDonnell, former archbishop of Canterbury Lord Carey, former Green Party leader Caroline Lucas, Margaret Thatcher’s former health minister Baroness Hooper and ex-leader of the Liberal Democrats Lord Campbell.
“The longer we wait to act, the more likely it is that dangerous variants could emerge that can evade the protections offered by current vaccines,” the letter said, which was co-ordinated by the all-party parliamentary group (APPG) on coronavirus.
It added: “The UK has an opportunity to use the G7 summit to show leadership on this critical issue and demonstrate that ‘global Britain’ is more than just a slogan.
“While the UK has rightly committed funding to Covax, we remain a net importer of Covid-19 vaccines.
“The APPG on coronavirus, therefore, recommends that the UK must immediately adopt a policy of vaccine matching, in which for each dose of the vaccine imported, one dose is donated to Covax.
“This will help meet the urgent demand for vaccines in low and middle-income countries around the world.
“The UK mustn’t miss the opportunity provided by the G7 summit to lead the way in promoting more equitable global access to Covid-19 vaccines.”
The 116 peers and MPs believe the UK should aim to become a “net vaccine exporter” once it has boosted its manufacturing capacity.
The decision to write to the prime minister came about after Professor Andrew Pollard, who helped develop the Oxford-AstraZeneca vaccine, warned the group that “many millions could die between now and September” if vaccines are not more widely distributed across the globe.
Germany, France and Italy are among European countries that have committed to donating at least 100 million doses of coronavirus vaccines to middle and low-income countries before the end of the year, the group said.
They highlighted that the UK government has so far only committed to donating surplus shots in future to Covax, they said.
Matt Hancock has previously said that the UK “has probably done more than any other nation to help vaccinate the world’s poorest” through its support for the Oxford vaccine, which accounted for almost a third of the global number of coronavirus jabs administered as of 19 May.
He said the government had also donated more than £500m to Covax, which has delivered vaccines to 120 countries and territories.
In November, the UK government decided to cut spending on its annual foreign aid commitment from 0.7% to 0.5% of gross national income.