The likes of Bangladesh, Vietnam and Nigeria will benefit from lower tariffs under the scheme. It will also help cut costs for UK firms, leading to lower prices for consumers by reducing tariffs on imports from low income and lower middle-income countries. It could, for example, mean lowering tariffs on rice from Pakistan and trainers from Nigeria. Up to 70 qualifying countries may be included.

       Ms Truss said: "Now the UK is an independent trading nation we have a huge opportunity to do things differently, taking a more liberal, pro-trade approach that leads to growth and opportunity."

       Foreign Secretary Dominic Raab said: "Cutting tariffs for poorer countries enables them to trade their way to genuine independence. I'm proud we lead the world in offering that opportunity."