Activists have carried coffins down Whitehall to highlight global Covid-19 deaths ahead of crunch vaccine patent talks.
The protest, organised by campaign group Global Justice Now, comes as a World Trade Organisation (WTO) intellectual property council meets to discuss a waiver for the patents of coronavirus vaccines and treatments.
Last year, India and South Africa called on the WTO to suspend its enforcement of patents amid the pandemic.
Since then, more than 100 nations, human rights groups, and influential figures such as former prime minister Gordon Brown have backed the call.
However, the UK, the EU, and Switzerland all oppose the move.
At the protest, pallbearers gathered around the statue of Millicent Fawcett at Parliament Square before marching down Whitehall.
A violinist played a funeral march as the procession made its way to Downing Street.
Dozens of people attended the protest dressed in black, with one woman wearing a veil.
Nick Dearden, director of Global Justice Now, called on the Government to “get out of the way” of an initiative by South Africa and India that will allow countries to ignore vaccine patents and manufacture jabs themselves.
“We’re here tonight outside the Prime Minister’s residence, outside Downing Street, to demand to him that he gets out of the way of the World Trade Organisation tomorrow and supports South Africa and India, to waive patents, to waive intellectual property, and to allow countries around the world to produce vaccines for themselves,” he said.
Mr Dearden added: “It’s absolutely shocking and shameful that so few people across the global south have been vaccinated.”
Global Justice Now claims that 3.5 million people have died of Covid since the patent waiver was first proposed last October.
It warns that vaccine donations are always “too little and too late”.
The UK is a major vaccine manufacturer, with the AstraZeneca vaccine among the first jabs to be rolled out around the world.