Calls for the UK to open the door to reparatory justice for slavery, colonialism and the worsening effect of the climate crisis are growing from Caribbean and African nations, campaigners and MPs as the Commonwealth heads of government meeting (Chogm) gets under way in Samoa.

The UN judge Patrick Robinson concluded last year that the UK owed more than £18tn in reparations for its historical involvement in slavery in 14 countries. But Downing Street has said the issue is “not on the agenda” at Chogm, and Keir Starmer said on Wednesday that he wants to be “facing forward” rather than have “very long, endless discussions about reparations on the past”.

Campaigners argue that in a number of Commonwealth nations, the generational impacts of crimes against humanity have been compounded not only by a modern-day system of debt that has favoured western interests, but also by extreme weather events, caused or made worse by the carbon emissions of wealthy nations.

The demands extend beyond the Commonwealth. The African Union, which also includes former French, Spanish and Portuguese colonies, has joined forces with the Caribbean Community (Caricom) to put pressure on former slave-owning European nations to engage with the reparations movement. Caricom has drawn up a 10-point plan for reparatory justice.

In Britain in recent years, organisations including the Guardian, the Church of England and the Bank of England have apologised for their links to slavery. The UK is yet to make an apology.

King Charles, in a speech to Commonwealth nations in 2022, said ways must be found to “acknowledge our past”, including slavery, which he had previously described as an “appalling atrocity”. But he has stopped short of saying sorry.

The Guardian spoke to experts and campaigners about why reparation is about much more than money – and the forms they think it should take.

Aid is not reparations

Likening the Commonwealth to an unequal family, Bell Ribeiro-Addy MP, the chair of the all-party parliamentary group for Afrikan reparations, said “we need to look at clearing debt”, as well as “climate resilience” and “returning artefacts”.

She added: “An apology is free. But the way in which we are not willing to apologise for one of the worst crimes in humanity speaks volumes. The next step has to be climate resilience – in Caribbean and small island states things are getting worse.

“At the moment our solution to problems is to give a bit of aid. Aid is not reparations, it has a lot of strings attached. The aid industry was meant to alleviate poverty, but it’s become an industry and all industries operate on supply and demand, so it benefits the industry to keep people in poverty.”

The Labour politician said there was a post-Brexit economic argument for treating Commonwealth nations as equals, having “left our closest trading partner to go out into the world” without recognising the postcolonial “ill will” felt towards the UK by fast-growing economies.

Economic justice

Washington Alcott, a reparations campaigner and researcher from Manchester, called for “anything that is going to upskill people and create employment opportunities”.

“In Jamaica, a lot of people are running their own businesses, but need skills for packaging and marketing to the international market. I’d like to see support for startups in Jamaica,” he said.

“Reparation should look at the fact that colonialism has taken out so much resource from the region and that that colonialism system was replaced by a neocolonialism system of debt that has ravaged the region and trapped it in austerity. For diaspora communities, reparation should tackle health. I would like to see serious investment in care facilities for older diaspora people.”

Talk to the people

Clive Baldwin, a senior legal adviser at Human Rights Watch, said reparations were an acknowledgment to people affected by human rights abuses, and so had to “engage with the people”, rather than being confined to “government-to-government” discussions.

The UK recently agreed to hand over Britain’s last African colony, the Chagos Islands, to Mauritius in an agreement that includes a right of return for Chagossians, whom the UK expelled from their homes in the 1960s and 1970s to make way for a US military base, with a commitment to “address wrongs of the past”.

Baldwin said how the UK enacted this promise to Chagossians, who are significantly descended from enslaved Africans, was important to the wider issue of reparations.

“The Chagossians are one of many examples of the ongoing impact of colonialism – the trauma is something that goes through generations and affects an entire people. If they can’t address that, what can they address?”

Recognise the impact on black Britons

Clive Lewis MP, who hosts the Heirs of Enslavement podcast, said: “If you’re not going to deal with the very cause of the structural racism in the most basic way, by an apology, then is it any more than window-dressing that you say we’re going to build a fairer Britain for black people?”

Lewis said the “baseline” for the UK government in addressing reparations should be the 10-point plan devised by Caricom, which has asked for a formal apology and debt cancellation.

Look to the EU

The Irish billionaire Denis O’Brien believes reparations to Caribbean nations could be modelled on the EU’s European regional development fund (ERDF), which has sought to reduce inequalities within Europe since 1975.

O’Brien, who founded the Repair Campaign for reparations, said the organisation was working in the Caribbean on plans modelled on the ERDF with the University of the West Indies. The plans would fund domestic social and development projects in 15 Caribbean nations, based on the Caricom 10-point framework.

“Our plan is for these social and economic priorities to be funded over 25 years,” he said. “We’re not advocating for money to be paid upfront, we’re saying this is going to fund maybe 30 initiatives in each country to socially and economically develop the country.”

You can’t put a price on human life

The head of the International Slavery Museum, Michelle Charters, said a “holistic approach” was needed.

“It might be financial, but should also be educational, cultural, and technological, so that ideas can be shared that are informed by the many experts in this field, including those with lived experience of the legacies of transatlantic slavery, who must have a voice,” she said.

“Personally, I am not in favour of putting a financial value on human life and suffering, as it was this dehumanising process that was at the heart of transatlantic slavery, so a one-off payment to those countries most affected by it does not feel appropriate in isolation.”

Don’t expect the struggle to end

Ngozi Fulani, the founder of the domestic abuse charity Sistah Space, said governments were avoiding taking responsibility because they “don’t want to pay”.

“So when you’re trying to have a conversation with someone who knows they’re guilty and won’t listen, we know that we have an extended fight on our hands and they should know this: we will not stop our fight for reparations,” she said.