ING Australia's decision to hike upfront fees paid by commercial borrowers could herald a new trend in the local banking industry that is bound to rankle small business advocates and the Morrison government.As margin erosion in the declining rate environment depletes returns from mortgages, banks are reviewing their fees on other lending activities - such as business credit - with a view to minimising earnings runoff.One of the options open to lenders is to reverse the sector-wide trend of recent years that has seen an array of bank fees either reduced or abolished altogether.While ING has made no public announcement about its planned fee hikes, it has begun to furnish details of the changes to brokers.From next Monday (September 16) new commercial borrowers will cop an upfront "commitment fee" of A$2000 when they apply for loans of up to $1 million from ING. That represents a doubling of the $1000 commitment fee currently levied on ING business borrowers. Borrowers seeking loans of more than $1 million will pay a commitment fee assessed at a rate of 0.2 per cent of the principal.ING gave no reason for the fee hike in the notification it sent brokers on Tuesday other than to say it followed a review.Nor did the bank provide a justification for commitment fees, which ING business customers are required to pay before their loan applications are assessed."ING regularly reviews our fees and charges," the bank told brokers in the notification."Our most recent review has resulted in an increase to the commitment fee for new commercial loan applications, where borrowings are less than $1,000,000."We will charge $2000 (previously $1000) on receipt of all new commercial loan applications using the credit card details provided on the commercial loan application form (note cheques are not acceptable)."ING's new fee grab on commercial borrowers could elicit a harsh response from political leaders in Canberra given the growing concern within the Morrison Government over the recent decline in private investment.According to the Australian Bureau of Statistics, private investment in the Australian economy fell by 1.6 per cent in the June quarter."Our focus now needs to be on how we can more effectively encourage business investment," said Treasurer Josh Frydenberg in August."It's a discussion which I am continuing to progress with the business community."While Frydenberg tries to induce new business investment in the economy with tax breaks, moves by other banks to hike fees levied on commercial borrowers could potentially ignite a fresh reputational crisis for the industry.Notwithstanding this risk, Canstar director Steve Mickenbecker believes more banks will be tempted to make up for lost revenue in their mortgage operations by making their business books more profitable."I think more banks will be looking to generate more income out of business banking to make up for the squeeze on margins in home loans," he said."When you see mortgage pricing falling below 3 per cent it becomes hard to make money out of a home loan portfolio."That's the pressure we're seeing now."