Fuel excise paid by Australian motorists will be halved for six months, part of a pre-election cash splash designed to help fight the rising cost of living and rebuild the Morrison government’s damaged political stocks.

From Wednesday morning, fuel excise will be cut to 22¢ a litre for petrol and diesel, down from 44¢ a litre, in the most significant change to excise since John Howard’s indexation pause in 2001.