Keep the taxes, then give the money back
I think this is a pretty interesting idea. Certainly preferrable to Stage 3.
You're never going to get away from the political difficulty of "breaking a promise" but something like this is the bold counter-argument you need to take.
I also think there could be some really good synergies if the government also decided to announce a windfall tax on LNG or mining companies.
A strong message of "Every Australian will get $700 instead of Stage 3 and then an additional $150 from our windfall tax. Every Australian should benefit from the sale of our natural resources not just foreign mining companies. This $150 will help families pay their energy bills which we know people are struggling with at the moment."
Politically, I think that's a pretty strong message.
I also tried to come up with a politically defensible alternative to Stage 3.