Mervyn King told a webinar session hosted by the Policy Exchange that he was surprised so many branches had closed.
"What we now need is the banks and the people who work in the branches to be there both on the telephone and in person if necessary to talk to businesses to so the emergency loans, which in principle are available, are available in practice."
The Government has decided to lock down the economy in the interests of public health, but by suppressing activity, businesses are being hurt.
The chancellor has announced a series of measures to ensure that companies don't run out of cash and to compensate both employers and employees for lost earnings.
But Mervyn King isn't convinced the schemes are working as designed.
He called on banks to issue "clear instructions" to their staff and to ensure that businesses can walk into their local branch.
Former Governor of the Bank of England, Mervyn King addresses a webinar hosted by the Policy Exchange
Lord King described banks as "part of the essential emergency system to keep the economy going" and said that - like supermarkets - branches should be open.
The anecdotal evidence suggests businesses are struggling to access the help on offer.
They report that banks are insisting on personal guarantees from directors, despite the taxpayer underwriting 80 per cent of every CBILS loan.
And they claim banks are over-charging.
Mervyn King believes that CBILS has design faults that need address.
He told ITV News that personal guarantees are unhelpful and that banks should be extending help under the CBILS scheme "interest free and with no arrangement fee".
We are heading into the mouth of what looks like a very severe recession. If the Government is to succeed in keeping businesses in business and workers in work then the evidence suggests it needs to do more to ensure that the help on offer reaches those who need it.
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