The Treasury has asked high street banks to assess their exposure to at-risk sectors and companies if a “no-deal” Brexit leads to a cash crunch for UK plc.

An executive at a London-listed lender told the Telegraph that ­officials at the Treasury had joined Bank of England regulators in urging banks to draw up plans to support businesses through any disruption.

UK banks have been privately drawing up plans to help UK firms through any cash flow problems for several months, in case a no-deal scenario ­results in delays to cross-border shipments or payments.

“We’ve been asked to assess our ­exposure to particular industries that have risks and have started having ­detailed conversations with our customer base about the risks as they see them,” the FTSE bank boss said.

The source said companies assessed to be most at risk of cash flow or credit problems include those reliant on overseas supply chains or just-in-time ­delivery such as food and drink sellers and retailers.

Exporters and firms exposed to foreign currency risks have also been identified as potentially hazardous for banks, the source said.