David Cameron should issue an apology to Jamaica and its people for Britain's "brutal" involvement in the slave trade, Jeremy Corbyn has declared. The Labour leader also promised to make such a statement if he won the 2020 general election.

"I think we should apologise for the slave trade and understand that the history of Jamaica is, yes, one of amazing joy and achievement since independence in 1962, but it's also a history of the most gross exploitation of people," the left-winger told the Press Association.

"The slave trade and the system of slavery was the most brutal part of our history and the history of Jamaica. I spent my youth in Jamaica, I lived in Jamaica for two years, and I love the country very much indeed.

The comments come after Cameron has been faced with mounting pressure over the issue. The Conservative leader promised to give the Caribbean £300m ($455m) in aid but his counterpart Portia Simpson Miller reportedly raised the issue of reparations during their meeting in Kingston.

Cameron has so far not publicly talked about reparations during the visit. But the issue may be raised when the prime minister makes a speech to the Jamaican Parliament at 1.15pm BST on 30 September. Former Labour prime minister Tony Blair went as far as expressing "sorrow" over the UK's involvement in the slave trade in a 2007 statement.

On the topic of economics for the Caribbean, Development Secretary Justine Greening, who has accompanied Cameron on the trip, said: "Too many Caribbean countries are held back because they remain vulnerable to severe economic or climate shocks. With some of the highest energy costs in the world, it is difficult for businesses to compete in global markets, leading to decades of slow or declining growth.

"Britain's close relationship with the Caribbean and our new support will help boost growth and kick-start economic recovery across the region as well as creating important trade and investment opportunities for the UK."