Ever since Tony Blair slid into power, politicians in the UK have been fond of claiming to be 'radical', whilst actually advocating and implementing rather conventional economic policies. So, as an antidote, here's a genuinely radical proposal I heard a few years back:
0% income tax, 0% expenditure tax, and 100% inheritance tax.
Nobody would pay tax during their lifetime, but their assets and capital would be taken by the government when they die. What would an economy such as this look like? Well, with 0% income tax people would have a greater incentive to work harder, so the economy would be larger. 100% inheritance tax would entail that a much greater proportion of the GDP would be taken in the form of taxation, so the government would be able to afford health and education services of an extremely high standard. Some people might try to liquify all their assets and spend all their money before they die, but unless one's time of death can be reliably predicted, this is a difficult game to play. It might also be argued that people would resist 100% inheritance tax, but when the average lifetime enters the 80s, it means that people will generally die when their offspring are in their 50s, and therefore, in most cases, established with a family, house and career.
Just a thought for Mr Cameron!