WA Premier aiming for third term

West Australian Premier Colin Barnett says he's fighting fit and intends to stand for re-election in 2017.

The 63-year-old Liberal leader, who's in his second term, says he will always do what's best for the party's prospects of returning to power.

"I'm enjoying my job. I feel fitter and healthier than I probably did 10 years ago, lost a few kilos," he told ABC radio on Thursday.

"I would hope to go on, but that ultimately is up to my colleagues. I'm certainly not ready to retire."

A recent Morgan Poll showed opposition leader Mark McGowan was WA's preferred premier.

But on a two-party preferred basis, the Liberals were still ahead.