The Department of Employment and Workplace Relations appearance at a Senate Estimates hearing has been characterised by a series of complex and confusing explanations of the Government’s so-called Closing the Loopholes Bill.

A phalanx of departmental officials was required to explain various parts of the controversial Bill. It often took two or three officials to contribute to the answer to a single question.

Shadow Minister for Employment and Workplace Relations Senator Michaelia Cash said: “One thing that was made very clear was that, despite what the Government keeps claiming, service contractors are not excluded from the labour hire provisions in the Bill.”

A departmental official told the hearing: “It is not a strict prohibition against the inclusion of services contractors.”

Senator Cash said: “It has been plainly obvious to everyone that service contractors are not excluded and now we have confirmation of this from the department which drafted the Bill.”

On the complexity imposed on business in the Bill, Senator Cash said: “A question and follow-up on the definition of a casual and the effects of that definition took over 15 minutes to explain. I think many in the room were more confused at the end of the explanation than at the start.”

“I’m not sure how small and medium business operators are expected to work their way through these changes and understand what they can and can’t do,’’ Senator Cash said.

“The information provided today raises even more questions which we will be exploring through the ongoing committee inquiry and also in the Senate when the Bill reaches the chamber,’’ she said.

“At one point an official admitted that ‘loophole is not defined in the bill’ and ‘it's a broad-brush way of referring to the measures in the bill to give it a short title’,” Senator Cash said.

“If it wasn’t so serious it would be laughable,’’ she said.

“At the start of the day we learnt how even the Department got it wrong when it came to paying their own staff. They underpaid 99 staff by over $60,000 and it has cost them nearly $200,000 so far in legal and other fees to rectify the situation,’’ Senator Cash said.

“If the Department responsible for employment and workplace relations can't get it right on paying their staff how can businesses navigate this whole system and the changes proposed?’’ she said.