The union used the Palmer United Party-led Senate Inquiry into the Queensland government to highlight what it said was "inexcusable mismanagement" by Energex executives, claiming it only deployed six crews between 11pm and 4.30am following the storm, in an effort to save money in penalty rates.

The storm cut electricity to more than 80,000 homes. Thousands are still without power.

But both Liberal Senator James McGrath and a spokesman for Energex both strongly disputed the claims on Friday.

The spokesman said the minimum number of crews working during that period was 42, with the average somewhere in the mid-50s.

"We wouldn't have them sitting in the depot," he said.

He blamed the enterprise bargaining agreement negotiations for the union's claims.

Senator McGrath challenged the ETU on its claims during the inquiry, making inferences the union was attempting to score points against the LNP.

But ETU Organiser Stuart Traill took umbrage at the Senator's allegations and said he had received the information from Energex staff.

"The information that we were given last night, was up until 11 o'clock there was 127 crews out working as part of the restoration process, so 127 two-person crews," he said.

"We were contacted throughout the night and again this morning from hundreds of ETU members that were ready, willing and able to participate in the response activities...but they told us that they weren't allowed to come into work until 4.30 this morning.

"The only explanation for that, is that Energex did not want to pay overtime rates to have them out.

"...The phone call I had at 8.56 last night with the person from Energex in control of the response specifically told me that there would only be a handful of crews through to this morning.

"The second in charge at Energex this morning confirmed with our senior ETU delegate that all Energex did between 11 and 4.30 was to double the stand-by crews...so we dispute the figures that Energex has provided."

The ETU submission also highlighted the links between the government and ERM Power.

The hearing, the second to be held in Brisbane, was a much more tame affair than last week, with only a few interjections from opposing Senators, with chair Glenn Lazarus able to maintain control with a few "you do not have the call" comments.

Senator Barry O'Sullivan was not present.

The hearings will continue, with the Sunshine Coast next on the tour.