An "aggressive" commercial property lender is embroiled in an investigation into its activities in the market after an MP expressed “grave concerns” in a letter to the Parliamentary Commission on Banking Standards, the Yorkshire Post reported.

According to Labour MP Clive Betts, Yorkshire Bank - owned by parent company National Australia Bank (NAB) – is “aggressively calling in loans that have not yet reached their termination date”.

The title states that Mr Betts had been contacted by dozens of customers of the bank who have urged investigation into its practices, however, Yorkshire Bank maintains that its commercial property loans continue to be managed in line with contractually agreed terms.

The Yorkshire Post reported that Mr Betts – who previously alleged that the Bank mis-sold loans to SMEs - said: “The past and present customers who have contacted me have varying stories to tell but almost all of them maintain... that the bank has sought to pressure them into repaying agreed loans in full and transferring their accounts to another bank.

“The pressure applied has been various, but particular attention has been drawn to the bank seeking revaluations of property with a view to invoking the value to loan clauses common to many such loans.

“Allegations of mis-selling of such products correspond to the concerns raised by the Financial Services Authority about interest rate hedging products by this and other banks.”

The allegations follow the news that Yorkshire Bank and its sister lender Clydesdale Bank – which used to provide a funding line to bridging firm Cheval - transferred £5.6 billion of commercial property loans to NAB last year after a restructure.

Sooner after, the portfolio reduced by £300 million in just one quarter, which the Bank has said was due to loans maturing or customers refinancing with other lenders.

The report further stated, however, that a study from the FSA found that over 90 per cent of interest rate hedging products Yorkshire and Clydesdale sold to small businesses broke its regulatory framework.

Mr Betts’ letter to the Commission also outlined that both Yorkshire and Clydesdale had previously failed to clarify concerns of mis-selling.

It was also reported that a spokesman for Yorkshire Bank, Barry Gardner, said: “We are happy to meet with Mr Betts to discuss the points he has raised, however, transferred commercial property loans continue to be managed in line with contractually agreed terms. Any customer with a complaint should contact us to enable us to investigate.

“We also remain fully committed to the review of agreed interest rate hedging products and proactively worked with the FSA during the pilot review process.

“We announced earlier this month that, subject to regulatory approval, we will start contacting customers with an in-scope product, prioritising those with the greatest need.”