Soldato
The whole advantage of having a pension taxed at a later date, is that you should be able to manage your pension income so that it's taxed a lower bracket. In theory you should have less fixed outgoings so you should need less incoming.. i.e. the mortage should be paid off and you don't need to pay for fuel to drive to work.
Also the main point that people aren't seeing that the moment is that IF they did get rid of NI and have single tax system, they will only add some if not all the NI tax to the income tax. Some people like ourselves who has been paying NI on our income in our working life will have additional tax added to our pension income, while currently pensions are not NI taxed.