After months of holding out against an 'out of cycle' lift in variable rate mortgages, an industry-wide round of rate hikes looks imminent as funding costs push steadily higher.One of the four oligopoly banks in Australia must be set to brave the media storm in a week where the banking news cycle will be defined by tales from the Hayne royal commission of harrowing and potentially illegal treatment of farming borrowers by banks. Hearings on this topic begin this morning in Brisbane.Two smaller banks late last week joined the (so far) short list of lenders that have lifted variable home loans rates. On Friday, IMB Bank notified that, from 22 June, its standard variable interest rate will increase by 0.08 per cent for new and existing home loan customers.Also making a move was Auswide Bank, which said it would increase interest rates on owner-occupied home loans by five basis points from 22 June. For investment home loans and residential lines of credit rates will be 13 bps.ME and Suncorp are among the few to have also raised variable rates at a time when banks are otherwise tinkering with the rates premium on investment loans. ME was an early mover, the bank lifting its variable rate by six bps as long ago as mid-April.The last industry-wide round of variable rate increases took place as long ago as December 2016. The Reserve Bank of Australia's monitor of "indicator lending rates" shows variable rate home loan pricing static at around 5.2 per cent since June 2017.Capital markets analyst Dr Philip Bayley, yesterday forecast an end to the fence-sitting."With the increase in the Fed Funds rate target the week before last in the US to 1.75 per cent to 2.00 per cent, markets are now looking very closely at the difference between interest rates in the US and here. Bank bill rates have moved up, with the 90 day rate increasing by five bps over one week and the 30 day rate increased by almost 10 bps," Bayley wrote in his weekly DCM Review."Banks haven't increased mortgage rates yet, but the fact is that their funding costs have been increasing all year so far, and while at the moment they dare not raise rates, the time when they do so is getting inevitably closer," Bayley said.The present ratchet in bill rates dates from around mid-May. The 30-day bank bill is up 19 bps over the six weeks since then and the 60-day rate 22 bps higher. Both the 30-day rate and the 60-day rate have pushed along by 40 bps over the last 12 months.Banks have had little scope to moderate funding costs among their deposit books either. The RBA's indicators show a lift in bonus saver rates (a key driver of new deposit flows), with a typical interest rate of 2.05 per cent, a rise of 15 bps over a year. Comparison service MoZo lists plenty of specials on bonus rates today in a range from 2.50 per cent to 3.05 per cent.