“That is why the chancellor announced at the Budget that we will continue to explore if this model could improve outcomes for savers.”

Ultimately, the problem is that it would not be building a new DC system from the ground up, which is what happened in Australia.

There are currently 26,390 trusts-based schemes, including 36 master regulated by TPR, and 1,830 contract-based schemes regulated by the FCA.  

And, as Rob Yuille, head of long-term savings policy at the Association of British Insurers, says: "It would be a perfectly valid system to introduce if you're starting from scratch. It's the change and implementing it that's more problematic than the concept itself.

"It's changing the incentives for consumers and employers."

Melanie Tringham is features editor at FT Adviser