Countries such as Jamaica, Pakistan and Ghana – which already pay little or no tariffs – could see the money they pay on exporting goods to Britain drop.

Liam Fox, international trade secretary, said on Saturday leaving the EU was “an opportunity to step up our commitments to the rest of the world”.

He added: “Behind the ‘duty-free exports’ are countless stories of people in developing countries working hard to provide for themselves and their families by exporting everyday goods such as cocoa, bananas and roses, resulting in lower prices and greater choice for consumers,” he said.

Forty-eight countries, including Bangladesh, Sierra Leone, Haiti and Ethiopia, already benefit from duty-free exports to the UK.

Their ‘everything but arms’ arrangement – whereby they pay no duty on everything they sell to Britain that is not arms and ammunition – will continue.

International development secretary Priti Patel said: “Building a more prosperous world and supporting our own long-term economic security is firmly in all our interests‎.”

About £20bn a year of goods are shipped to the UK from developing countries, which accounts for around half of the country’s clothing, a quarter of its coffee and other goods such as cocoa, bananas and roses.