Dealers could see business rates rise in line with inflation which according to the Retail Prices Index (RPI) has soared above forecasts to 5.6%.
Property consultants Colliers International believes rise "couldn’t have come at a worse time".
John Webber, head of rating at Colliers International, said: “Although business rates do not have to increase in line with RPI, the chances are that they will, and this means that businesses will be left facing a rise of 5.6% on their costs from next April, leading to an extra £1 billion for the Government.
“This rise is the highest since June 1991, and will hit businesses when they cannot afford it. We need to continue to put pressure on the Government to make life easier at a time when businesses are finding it hard to cope, not piling on additional pressure."