BACK to the future? Senior Liberal Tony Abbott's plea to strengthen the bedrock of marriage by reintroducing the option of a fault-based system for divorce has been met with a whimper of support.

Although Deputy Opposition Leader Julie Bishop said yesterday she was willing to entertain the idea - or at least debate it in the Coalition party room - experts suggest it could provide carte blanche for detectives to once more peer into the nation's bedrooms.

Yes, really, there was a time - before no-fault divorce was introduced via the Family Law Act in 1975 - when figures in trench coats would scour bins for hotel receipts to produce evidence of adultery, and a spouse's "marital fault".

This, in turn, could determine the size of a property settlement in court and even who got to keep the kids.

Although a generation has grown up with no knowledge of these punitive arrangements, Ms Bishop said she was willing to talk about Mr Abbott's proposal.