Rishi Sunak has been confronted over growing calls for the UK to make reparations to the victims of the slave trade.
The PM was urged to go further than the "sorrow and deep regret" expressed by his predecessors and commit to making payments because of Britain's role in slavery.
Earlier this year Grenada's Prime Minister, Dickon Mitchell, called on Mr Sunak to open talks about reparations.
Today Labour MP Bell Ribeiro-Addy called on the PM to acknowledge the wealth Britain accumulated as a result of colonialism and slavery and offer a "full and meaningful apology".
Ms Ribeiro-Addy said she and others had been calling for this for decades, and urged the Government to finally answer a call made by Labour stalwart Bernie Grant at his last PMQs.
She said: "This month marks 23 years since the passing of the late, great Bernie Grant, a former member of this House and a founder of the UK reparations movement.
"In his last PMQs before his death he asked for an apology for people of African descent, living and dead, for our country's role in slavery and colonialism.
"But since then Prime Ministers and heads of state have only ever expressed sorrow and deep regret.
"These are not sentiments that are befitting one of the greatest atrocities in human history."
The Labour MP continued: "There's been no acknowledgement of the wealth that's been amassed or the fact that our country took out the largest loan it ever has to pay off the slave owners and not the enslaved.
"So I'd like to ask the Prime Minister today if he'll do what Bernie Grant asked all those years ago, what I've asked and what countless others have asked and offer a full and meaningful apology for our country's role in slavery and colonialism and commit to reparatory justice."
See Mr Grant's exchange with Tony Blair in the tweet below
But this call was rejected outright by Mr Sunak.
He said: "What I think the focus should be on is of course understanding our history and all its part and not running away from it. But right now making sure that we're a country that is inclusive and tolerant of people from all backgrounds."
Mr Sunak added: "Trying to unpick our history isn't the right way forward and isn't we will focus our energy on."
Following the exchange, Keir Starmer's spokesman said: "She is right to highlight the appalling history of the slave trade and that is something we agree with what she was saying.
"On the specific point of reparations, the point she was making is not Labour party policy."
In a Westminster debate last month, Labour's Clive Lewis urged the government to follow the example of a wealthy British family who apologised for their ancestor's exploitation in Grenada by pledging to fund community projects.
Mr Lewis said: "The issue of reparations could be dismissed as the obsession of a small group of so-called woke extremists.
"We've seen a political backlash often on the benches of the members opposite at any notion that we should reassess our own history as regards colonialism and slavery and the impact it has and continues to have on millions across the globe and here in the UK."
He pointed out that former slave owners were awarded billions of pounds in today's money in compensation - with the last payment made in 2015.
"It was the slavers and the slaves themselves who received the vast sums - billions in today's money... they only finished paying it off in 2015, Mr Lewis said.
Mr Lewis praised the wealthy Trevelyan family, whose ancestors were compensated when slavery was abolished in 1833 - but the 1,000 people they "owned" in Grenada were not.
They pledged £100,000 to a community fund to help economic development on the island, and were in the Westminster Hall gallery as the debate took place.
Mr Lewis said the UK government must do the same to put right "400 years of the most hideous abuse".
He said: "There's no future worth looking forward to in the Caribbean until we confront the past. Go to the Caribbean and what you'll see is the past alive and well today - poverty, racism, inequality and debt."
Voicing her agreement, Labour's Dawn Butler said: "Reparations is about making amends for centuries of violence and discrimination, it's really interesting that people say let's forget what happened when countries are still in debt."
And Ms Butler told the debate: "Any arguments against this is not only a betrayal but a collusion with what happened centuries ago."
Mr Mitchell, Prime Minister of Grenada, invited Mr Sunak to attend talks with the Caribbean Community (CARICOM) about slavery reparations earlier this year.
He said: “As a head of government, I want to take this opportunity to join in a public request to my fellow head of government of the United Kingdom to accept our kind invitation to commence dialogue in an open, transparent, frank and dignified manner to talk of the need for reparative justice for the citizens of CARICOM."
