Debt won't fall to levels seen under the previous West Australian government while big developments continue in the state, Premier Colin Barnett says.

Labor has frequently reminded voters that debt was at a mere $3.6 billion in 2008 under the party's leadership compared to more than $18 billion by the end of this financial year.

But Mr Barnett says major projects are needed to support the ever-growing state's needs amid mounting industrial requirements and population growth.

Asked during a live debate on ABC television on Tuesday night if a re-elected Liberal government could reduce debt to 2008 levels, he said: "I don't think so if we continue to build major capital projects".

WA was going through a unique period of growth and the Liberal party had grasped it, Mr Barnett said, listing its achievements as including getting major projects such as Gorgon off the ground. Its future rail plans would mean more debt, he said.

"This is the decade for action," he said.

"If this is the Asia Century, this is the Asian decade right now and this state is going ahead because this government does make decisions.

"Yes, we've borrowed more money because we're striking out and we're getting the big projects. "We will bring debt, and level it off in the second term.

"But we are well within control."

Mr Barnett said the state government would continue to achieve surpluses, but conceded it had no savings measures other than to keep public sector costs down.

Labor only kept borrowings down because it benefited from the property boom, he said.

State opposition leader Mark McGowan said WA Labor didn't create the state's current debt situation, "but obviously if we were elected, we'd have to deal with it".

And it had a good record in keeping debt down, Mr McGowan said.

"What you have to do is make tough decisions," he said, referring to last week's announcement that the opposition would change or axe major projects and spending planned by the Liberal party.

He took a swipe at Mr Barnett's new office, dubbed The Premier's Palace, and said most of the big projects that had been completed under the Liberals had started under Labor.

"What actually developments are there that Mr Barnett has delivered in his term of office? The only new one that I can think of - conceived, planned, built and occupied - is his own new office," Mr McGowan said.

"All of the other plans were ones that were already in place and what West Australians are seeing is a massive increase in debt.

"On top of that, unemployment has gone up and I think industries other than the mining industries need a fair go because they're not getting enough attention from the state government."