More than three quarters of UK chief executives are thinking about shifting operations or headquarters abroad following the Brexit vote, a report has revealed.
Research by KPMG found that 76% of bosses would consider making the move in order to maintain trade links with the European common market.
However, 69% said they are confident about the country's growth prospects over the next year, while 73% expect their own company to expand.
"CEOs are reacting to the prevailing uncertainty with contingency planning," Simon Collins, KPMG UK chairman, said.
"In particular, the majority said they are considering relocating their headquarters or operations outside the UK.
"Over half believe the UK's ability to do business will be disrupted once we Brexit and therefore, for many CEOs, it is important that they plan different scenarios to hedge against future disruption."
The survey collected responses from company bosses in charge of firms with revenues of between £100 million and £1 billion.
It revealed that 62% of bosses believe global economic factors will have the biggest impact on growth over the next three years.
"We hear it time and time again that business needs certainty," Mr Collins added.
"Policymakers should be really concerned about a leaching of British business abroad and should engage with business early to understand what assurances they can offer and closely monitor any shifts overseas."
The report comes after banking bosses warned at the beginning of September that huge risk and harm could be inflicted on London's financial services sector if the industry is not given enough time to adjust to Britain's future trading relationship with the EU.
The sector may need two to three years to adapt to a new trade deal without harming financial stability, according to Alex Wilmot-Sitwell, head of European operations at the Bank of America Merrill Lynch, who was giving evidence to a House of Lords sub-committee.