The research shows that companies resorting to unsecured borrowing in response to a low valuation can expect to pay more than double the rate of interest, compared with loans secured against an asset.

On average, members of the Forum’s Economy Watch panel faced interest rates of 11.8% on unsecured borrowing, in comparison to 4.5% for secured lending.

Last week figures released by the Bank of England showed that the banks’ net lending has fallen by more than £50 billion in the past year, with small business struggling to secure loans.

Business owners are blaming increased security demands as one of the reasons they are failing to secure credit. The FPB cite low valuations as a large part of the problem.

In one specific example, Gordon Hazelton of Glasgow told the Telegraph newspaper he believed his property had been undervalued by up to £100,000 when he was negotiating finance.

Andrew Bacon, of business property specialists LeaseholdersUnited, is the Forum’s advisor on property issues. He said: “One of the root causes of the crisis of lending on commercial property is the lack of transparency in the UK’s commercial property market.

"This has left many valuers with inadequate market data that, given economic conditions, will make them more pessimistic resulting in lower valuations on commercial properties.

“This means many banks will subsequently have a limited appetite and ability to lend to businesses.”

Banks currently rely on independent valuers – who must act within the guidelines of the Royal Institution of Chartered Surveyors Red Book – when pricing property.

Banks are entitled to tell the valuers which method to use, and can request they value a property on the assumption that a sale will be made within 180 or 90 days, for example.

A spokesperson for the British Bankers’ Association spoke to the Telegraph newspaper, and said: “In an uncertain economy there are bound to be different views on how much a property is worth. But banks do not lend against security alone – their focus will be on the ability of a business to generate sufficient income to meet its financial commitments.”

LeaseholderUnited have developed an online tool called CostMINDER in an attempt to provide a solution to the problem.

CostMINDER enables users to input the details of any shop, office or industrial premises in England and Wales in order to obtain an independent assessment of its value.

By Dawn Murden