McGowan cabinet expected on Thursday

Incoming WA premier Mark McGowan will likely unveil his cabinet line-up on Thursday, which is expected to include a new position.

He has to reduce his front bench from 21 in opposition to 17, but has indicated he'll have a cabinet secretary in his ministerial team.

"(Former Liberal premier) Richard Court had one and I think it worked well. There is a prospect of us doing that," he told reporters on Tuesday.

The Labor caucus, which could have as many as 41 members, will meet on Wednesday to discuss the cabinet.

But Mr McGowan says he'll have the final say of who's in and the portfolios they will hold.

"I'll be respectful of people's ability, I'll be respectful of of the regions and I'll be respectful of of people who have been there a long period of time and deserve the opportunity," he said.

"We'll get a good team."

Alannah MacTiernan, who is returning to state politics after one term in Canberra, is expected to be parachuted into cabinet - forcing out an existing frontbencher.

She has said she wants an economic portfolio to help diversify the state's economy.

Meanwhile, Mr McGowan said he was not going to lose sleep about how he would handle the upper house.

There'll be around seven representatives from minor parties, including two from One Nation, to negotiate with, as well as 14 from the Liberals and Nationals. Labor looks like having 15 in the 36-seat chamber.

"It's not something I can control."

He said he would not make deals or give the minor parties special favours to get his government's agenda through.

"Just vote on the merits of the legislation, it's not too much to ask," he said.

He attacked the Liberals for the preference deal with One Nation, which he said was a mistake.

"The Liberal party is responsible for those One Nation members being in the upper house."