Tasmania's Treasurer has been accused of “having a tantrum” over the difficulty of passing key bills including the TasWater takeover.

The state’s Legislative Council has a new makeup following the election of Labor's Joanna Seijka.

Treasurer and Local Government Minister Peter Gutwein said it would now be “nigh on impossible to get legislation through”, with Labor's numbers in the independent-dominated Legislative Council now at four, leaving the Government with only one seat.

It means three pieces of legislation — phasing out suspended sentences, introducing mandatory prison sentences and the TasWater takeover — could be dead in the water, with Labor saying it will vote down all three.

It is good news for the councils that collectively own TasWater, with owners’ representative David Downie welcoming the Treasurer's comments.

“I was very encouraged that that Treasurer's backing down on his attempt to takeover TasWater from local government,” he said.

He said the Treasurer needed a new approach to passing legislation.

“He is trying to be very much like a bulldozer, but he would probably achieve more by trying to be more consultative and work with the legislative councillors,” Mr Downie said.

“It is a true democratic body, and it should be a democratic process, not a process of executive power trying to dictate to an elective body.”

Greens MP Andrea Dawkins said the Government needed to try harder to create legislation that the Upper House would support.

“I think Peter Gutwein sounded like a spoilt child who was having a tantrum when he made the statements, not pushing and processing the Government's agenda,” she said.