The 46-year-old African American was filmed gasping and pleading “I can’t breathe” as a white police officer, Derek Chauvin, kneeled on his neck for almost nine minutes.
The officer has since been fired and charged with third-degree murder and manslaughter.
As protests convulsed cities from coast to coast for a seventh consecutive night, President Donald Trump threatened to deploy the US military to quell the most serious wave of civil unrest since 1968.
On Sunday thousands of demonstrators broke social distancing regulations to gather in Trafalgar Square for a “Kneel for Floyd” protest, while hundreds marched through Peckham and Brixton in south London on Monday.
Both protests were organised by London chapters of the Black Lives Matter movement.
An activist speaking on behalf of these organisers said Wednesday’s action in Hyde Park, as well as further demonstrations at Parliament Square and the US Embassy this weekend, would be "larger than anything we saw in previous Black Lives Matter protests”.
He told the Standard: “We want as many Londoners to join as possible. We hope people will engage in action in any way that they can, whether it be a protest or whether it be supporting an existing campaign or otherwise.”
The spokesperson said the protests were organised to "show solidarity with the people of the US, particularly black Americans" and because "the injustice in the United States has refocused the similar problems we have here in the United Kingdom”.
He added: “Since 1990 almost one person a week has died at the hands of the police or prison system in Britain, and we need accountability and reform here as well.
“This crisis has to stop if we don’t want to go in the same direction as the United States.
Now a worldwide movement, Black Lives Matter was founded in 2013 in response to the killing of black teenager Trayvon Martin in Florida.
The latest demonstrations have not been endorsed by the London chapter’s umbrella group Black Lives Matter UK, which is “currently not calling protests due to the life-threatening reality of the pandemic”.
The spokesperson for Black Lives Matter London defended calling for mass gatherings amidst the coronavirus crisis, and urged demonstrators to wear face masks and gloves.
It comes after a report by Public Health England confirmed that people from BAME backgrounds are more at risk from Covid-19.
The spokesman said: “It’s a very difficult situation, where black people are disproportionately dying of Covid-19, but black people are also disproportionately dying in the police and prisons system. People should not be made to choose between one or the other.
“Given the very urgent situation which is taking place at the moment in the United States, and the fact that we are seeing an escalation of stop and search and other forms of policing in this country at the moment, we are going to have to work very hard to have to try and tackle both these crises. That is what we are trying to do.
“We just can’t expect people to stay in their homes and to stay indoors when this crisis is taking place in our police and prisons system.
“We are just urging people to stay as safe as possible during these protests. To wear gloves, to wear masks, to do everything that they can."
The charity Stand Up to Racism is also calling for demonstrations, asking Britons to assemble in a socially distanced manner at 6pm on Monday in cities around the UK to demand justice for Mr Floyd, as well as a “public inquiry in Britain into the disproportionate BAME deaths” during the coronavirus crisis.
A Metropolitan Police spokesperson said: "We will have an appropriate policing plan in place."