Small Business Minister Gordon Hill says business has been duped by the Opposition's promise to abolish payroll tax.
"They are starting to back-pedal furiously," Mr Hill said.
"They first promised that payroll tax would be abolished by late next year, then said it would only happen if a Federal Liberal Government won power and with a Goods and Service Tax in place.
"On ABC radio's Wednesday AM program, Mr Court admitted that without a Federal Liberal Government in power they would need eight years to abolish it.
"By last Monday, deputy Liberal leader, Colin Barnett had already admitted the tax might be lower after eight years, but might not be completely abolished.
"Hendy Cowan has now cast further doubt on the promise, conceding that the commitment rested heavily on a coalition victory at the Federal election, so that it would be difficult to abolish payroll tax without a Hewson government in power.
"In addition, Mr Court has been forced to admit that tax increases would be needed to fund his election promises, Mr Barnett says Government programs would be axed and hedges on his payroll tax promise.
"Their promises are a hoax.
"They claim they are sympathetic to the concerns of small businesses, yet are willing to shackle them to a GST policy if a Federal Liberal Government wins office and if not, offer the cold comfort of reductions in payroll tax over a period of eight years or longer.
"Unlike the Opposition, the Premier has unequivocally stated that she will abolish payroll tax for all small businesses.
"No Goods and Service tax would be imposed, and the Premier's pledges have no strings attached to Canberra."