A swathe of Britain’s biggest retailers are urging the Government to speed up planned changes to import tax exemptions which they say are giving overseas online sellers an unfair advantage.Asos, Marks & Spencer, Primark and Next were among firms to sign a letter to the Prime Minister and Chancellor which suggests imposing a £2.60 charge on each small parcel sent to the UK.The high street firms have criticised a loophole that allows retailers based overseas to send small parcels worth less than £135 to the UK without paying import duties.Chinese online giants Shein and Temu have rapidly grown in popularity in recent years thanks to their huge array of products, including fashion and homeware, and low prices.Chinese retailer Shein has ballooned in popularity over recent years (James Manning/PA) (PA Archive)This so-called “de minimis” threshold has become a “structural advantage for overseas retailer without a footprint in the UK, who undermine retailers that employ millions of people across the country, pay local taxes and pay import duties”, the letter read.Chancellor Rachel Reeves confirmed plans in the 2025 autumn budget to follow in the footsteps of the US and Europe and review the customs loophole, saying she wants to “support a level playing field in retail”.But the proposed reforms are not expected to be in place until 2029.US President Donald Trump took action to scrap exemptions for low-value imports last year, which had previously allowed parcels worth less than 800 US dollars (£595) to enter the US without paying any tariffs.The EU is also changing the rules so that parcels worth less than 150 euros (£112) will no longer be duty-free and is proposing to impose a three euro (£2.23) charge per item.The industry letter said that since the US changed its rules, there had been an “immediate switch in overseas retailer focus into the UK and EU, exacerbating this structural disadvantage for UK retail”.The UK is becoming an outlier, with a growing share of LVI (low-value imports) trade being directed into the UK market, it read.The retailers argued that a £2.60 flat-fee on each parcel sent to the UK would raise £1.7 billion for the Government a year and could be introduced quickly and temporarily like in the EU.Changes will also encourage people to spend at retailers with a UK presence and improve product safety checks, according to the firms.Other retailers to sign the letter including Currys, Halfords, Kingfisher, Argos, New Look and George at Asda.