That's the stark warning from council leader Nic Dakin as cabinet members grapple with budget figures that point to a spending shortfall from April this year.
A special full council meeting on Thursday 14 February will agree council tax levels for each of the different property bands. The charges take effect from April.
Cllr Nic Dakin said everything possible was being done to keep any increase to the absolute minimum.
'The council has made real progress these last three years. Three years ago the increase was just 2.1 per cent. Two years ago, it was lower still at 2 per cent. And a year ago we managed to keep the increase to only 1.9 per cent.
'We have achieved all this - some of the the lowest increases over the last three years anywhere in England - while protecting frontline services, including the money that is made available to our 85 schools.
'But the figures this year do not look good. Meetings have taken place daily to find more cuts to non-essential services. We have sent our officers back with instructions to find more reductions, and this has certainly helped make the position look better than it appeared a couple of weeks ago.
'Yet we are quite a way from being able to say that we can repeat the last three years of very low increases and protect the services the public say they want.
'This year it may be that services which have been taken for granted will have to be looked at. That will not be popular. Or if that is not possible, we will have no option but to put to the full council on 14 February an increase of more than double the rate of inflation - maybe as high as 6 per cent.'
Cllr Dakin said that North Lincolnshire people are not fools. They know that there must come a time when it becomes no longer possible to achieve both very low council tax increases while protecting all council services.
'I have no intention of seeking to mislead. Hard decisions have to be made, and will be. When the ruling Labour group's plans are put to full council next month, everything will be set out. In the meantime, the work will go on to find yet more savings.'
Approx. 7 out of ten (73 per cent) properties - some 48,000 - in North Lincolnshire fall into the bottom two council tax bands A and B. Just one in 12 fall in the so-called average band D.