Western Australia’s Labor government has added a $5000-per-household rebate and interest-free loans of up to twice that to encourage home battery systems to a list of non-means-tested handouts worth hundreds of millions of dollars ahead of an election it is nearly certain to win.

The pledge, made by Premier Roger Cook before the party faithful at the official campaign launch for the March 8 state election, comes amid warnings from the Reserve Bank and other credible economic sources that the high level of spending by the states is making the fight to tame inflation more difficult.