Clydesdale granted Andy and Moira Pearson, who run award-winning Tweed Homes, the £2.5 million overdraft in 2007 to finance their plan building new homes on land in the Borders.

However, according to the couple’s claims, they suffered “anguish, anxiety and stress” for seven years after suddenly being refused further access to the money without explanation, after using about half of the fund.

They also claim that they were left powerless to stop the racking up of massive charges which appeared as arrangement fees, exit fees and security fees.

They ended up footing a bill for fees that totalled more than one third of the sum they actually borrowed.

Lawyers acting for the Pearsons have now lodged a legal action against Clydesdale Bank in Edinburgh’s Court of Session which sets out claims that the Clydesdale breached its contract with them.

They are seeking £2.3 million in damages.

“Tweed Homes has been trying to settle matters amicably with Clydesdale for some time,” Mr Pearson said.

He added: “Our case has been passed from pillar to post for too long. We have finally lost patience with the bank and now find it necessary to try to achieve satisfaction through the courts.”