“…they also get a proportionately bigger tax top-up from the government…”
Er…no. They get a proportionately bigger sum in tax relief because they are earning proportionately more and paying proportionately more in tax. If the money had not gone into a pension it would have been taxed at their prevailing rate. So not a “top-up” but an allowance to keep more of their own dosh for taxation at a later date. Not quite the same thing at all.
The principle is that money set aside for a pension is not taxed because it is taxed when it is withdrawn. One of the main reasons retaining the status quo is favourable is that politicians cannot be trusted. Today’s Chancellor may well decide to tax pension contributions now on the understanding that they will be tax free on withdrawal. But thirty years is a long time in politics – in fact it is aeons. A future Chancellor may well decide that, despite the cash being taxed upon deposit, the “concession” allowing it to be withdrawn tax free “is no longer sustainable” and so it will get taxed twice.
It is not only the Chancellor’s wealthy chums that benefit from this. It is also people like senior nurses, police officers, London Underground train drivers – a whole host of people in fact who have, by “fiscal creep”, been dragged into the 40% tax bracket. Many of them are not, by any stretch of the imagination, “wealthy”.