UK aid efforts are being undermined by trade policies that risk driving people in developing countries deeper into poverty, campaigners have warned.
World leaders including David Cameron are set to adopt United Nations Sustainable Development Goals (SDGs) later this month, which aim to end global poverty and reduce inequality.
But trade policies such as a reform of the European Union sugar market, backed by the UK Government, are risking the livelihoods of hundreds of thousands of sugar cane farmers in poor countries, the Fairtrade Foundation warned.
The UK is a big aid donor, and the only country in the EU to have met the target to spend 0.7% of national economic output on aid.
But the Government was in danger of "giving aid with one hand and taking away through trade rules with the other", if it did not make trade measures fair, the foundation said.
Campaigners are concerned the reforms to the sugar market are just one example of policy incoherence, with the Transatlantic Trade and Investment Partnership (TTIP) currently being negotiated between the US and Europe potentially making things worse for people in poor countries.
Countries outside the US and Europe are not included in the TTIP negotiations, but it is feared their impacts will cut exports from developing countries to the EU and US - with agricultural products and manufactured goods such as garments particularly affected.
The EU reforms to the sugar market, which will remove a cap on EU sugar beet production, are set to push 200,000 people in African, Caribbean and Pacific countries into poverty by 2020.
Lifting the cap means small-scale sugar cane farmers will be unable to compete with European sugar beet farmers, who receive subsidies under the EU's Common Agricultural Policy.
New independent research by the Fairtrade Foundation reveals that Mozambique and Swaziland alone stand to lose out by more than 40 million dollars (£26 million), and leave producers exposed to the world market which will hit their incomes.
The Fairtrade Foundation is urging the UK Government to ensure the SDGs are "pro-poor" so they drive fair and sustainable trade, and to take a joined-up approach across departments to deliver poverty reduction through trade.
It also wants to see impact assessments of the likely affects of trade decisions on poor communities, measures to ensure farmers and workers affected by changes to trade regimes are supported properly so they can adjust and for the UK to use its influence to make sure EU trade decisions deliver fair outcomes for poor producers.
Michael Gidney, chief executive of the Fairtrade Foundation, said: "Trade is a powerful way to lift poor countries out of poverty.
"The UK Government must make sure its rhetoric on sustainable development is backed by its trade policy.
"We need the poor to come first and the SDGs are a unique opportunity to initiate fairer, more sustainable trade.
"Otherwise it's a case of giving aid with one hand and taking away through trade rules with the other."