Treasury officials have warned the federal government that the Hayne royal commission into banking misconduct could have a negative impact on consumer demand.Peppered throughout the Treasury's economic outlook statements are references to the possible dampening of household spending that could stem from further tightening of lending standards in the banking system."A change in households' attitudes towards saving, combined with subdued income growth, may result in a slower consumption growth than forecast," the government observes in its outlook statement."There is also a risk that household spending may be affected by any unanticipated tightening in financial conditions, possibly as a consequence of the Royal Commission into Misconduct in the Banking, Superannuation and Financial Services Industry, although it is too early to assess how likely that is to occur."Factored into the government's budget assumptions is its forecast for dwelling investment to fall by around 3 per cent in the current financial year.While Treasury did not articulate precisely how the royal commission might impact consumer demand, analysts suggested the commentary pointed to expectations that commissioner Hayne was likely to spotlight weaknesses in responsible lending laws in his interim report.Tim Dring, head of Ernst & Young's banking practice, said supervised banks were already tightening lending standards in response to the crackdown by the Australian Prudential Regulation Authority."What we are seeing through the royal commission are examples where responsible lending laws were not adhered to and that will put more pressure on banks to use a loan applicant's actual expenses rather than modelling when assessing applications," he said."I think there is a risk the heightened scrutiny of practices in the mortgage and consumer finance markets could lead to a slowdown in lending activity."The government currently expects household consumption to grow by 2.5 per cent next financial year.