If this happens - and it has been mooted before - it would be hugely progressive. Pension tax relief costs £39bn per annum - and overwhelmingly benefits the rich. 
I've long argued that giving huge sums of public money to incentivise those with excess income to save that excess income is bananas (what else will they do with it)? ft.com/content/d39ed0…
I worked hard - but without success - to persuade the Shadow Chief Secretary to the Treasury that Labour should adopt something like this. Its 2017 Manifesto promised to take a look at tax reliefs for business but not their wasteful use to benefit wealthy individuals.
