Britain must pay reparations to former Caribbean colonies subjected to "400 years of the most hideous abuse" or it will be guilty of "collusion" with slavery, MPs have been told.
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 told a debate in Parliament that Britain must confront its past and commit to putting it right.
It follows calls by Grenada's Prime Minister, Dickon Mitchell, for Rishi Sunak to open talks.
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.
"Just think about that. The people who for 400 years have been brutalised who came to rebuild this country paid their taxes to pay their former slave masters."
And 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."
He said the former colonies are full of "potential that need to be realised", but said that when Britain withdrew, three quarters were unable to read or write.
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."
She continued: "Thre's a lot of reparations that need to be done, whether it's economic or acknowledgement."
And Ms Butler told the debate: "Any arguments against this is not only a betrayal but a collusion with what happened centuries ago."
Also backing Mr Lewis's call was Labour MP Nadia Whittome, who told the debate: "The reason why reparations are the right and fair thing to do is yes because of slavery and the wealth countries like ours extracted and underdeveloped these countries but also the climate crisis which threatens the very future of the Caribbean."
Last week Mr Mitchell, Prime Minister of Grenada, invited Mr Sunak to attend talks with the Caribbean Community (CARICOM) about slavery reparations.
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."
