That's what several railroad and coal-mining companies said Thursday. They urged the Legislature to reject a plan by Gov. Rod Blagojevich to repeal a rule that exempts such vehicles from motor-fuel taxes.
The governor says the change is needed to help fill the state's budget deficit.
A group called the Coalition for Fair Fuel Taxes says freight trains would buy their diesel fuel in other states. The coalition also says the tax could force some companies to close.
The Knight Hawk mine in far southern Illinois, for example, would have to pay an estimated $800,000 a year for its mining rigs, and owner Steve Carter says that might run him out of business.