The mural is expected to stretch for hundreds of metres along the southern bank of the River Thames outside St Thomas’ hospital, where Prime Minister Boris Johnson was put in an intensive care unit after he contracted the virus and fell seriously ill last year.

It has been organised by the group Covid-19 Bereaved Families For Justice UK, which has called for a public inquiry into the government’s handling of the pandemic.

“Each heart is individually hand-painted (and) utterly unique, just like the loved ones we’ve lost,” said Matt Fowler, co-founder of the group. “Like the scale of our collective loss, this memorial is going to be enormous.”

Britain’s government has promised to build a permanent memorial once the pandemic is over.