Brexit is making it difficult for firms to decide whether to import or export, hampering British trade, according to a new survey.
Research by the British Chambers of Commerce (BCC) indicated that half of businesses have to consider uncertainty over Brexit when deciding whether to trade internationally.
The BCC said its poll of 2,500 firms highlighted the economic cost of the "persistent lack of political clarity".
Half of firms were also concerned by the related issue of exchange rate volatility, which can increase the cost of raw materials and potentially make UK exports less competitive, the BCC added.
BCC director-general Dr Adam Marshall, BCC Director General, said: "Firms have been dealing with uncertainty over the future relationship with the EU since the referendum vote over two years ago.
"However, this survey shows that, as we get closer to the crunch, the lack of precision is starting to have a material impact on their decision-making.
"While business faces uncertain times, our research shows that businesses who do trade internationally are more innovative and dynamic compared to those who just focus their attention on the UK market.
"It is vital that clear progress is made in Brexit negotiations to give firms confidence and empower them to take risks and try to break into new markets, creating the Global Britain this Government so often talks about."
Shannon Diett, of DHL Express UK, which helped with the study, said: "The uncertainty expressed by British businesses taking part in this survey mirrors the increasing concern we are hearing from our customers, both of which further highlight the criticality now surrounding the Brexit negotiations."
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