The former Labor Premier Paul Lennon is warning Tasmania's unemployment rate could return to double-digit figures without a major development like a pulp mill.

Mr Lennon returned to Parliament House today after an absence of four years for the unveiling of his official portrait by Tasmanian artist, Geoff Dyer.

He told a ceremony to commemorate his tenure that he regrets leaving politics before the pulp mill project in the Tamar Valley was realised.

"And my goodness don't we need it now," he said.

"Back in the period 2006 to 2008, there were many people in Tasmania who thought we didn't need any more development, we had enough, we were right for the rest of our lives.

"I think we've found out different now, that if we're not careful we'll be back where we were in 1998 very quickly."

Mr Lennon says he has a simple message for Tasmanians, and that is to support the development of the pulp mill pioneered by the collapsed timber company Gunns.

"If we don't I have great fear for manufacturing in this state and for our ability to attract ability from outside of the island," he said.

The Premier Lara Giddings says her most pressing concern is the threat of a Tony Abbott Government and his plans to redistribute the goods and services tax.

"Firstly let me say we're not where we were in 1998," she said.

The Premier says Labor still supports the pulp mill.