Petition Introduce Additional Voluntary Taxation

A number of wealthy people have been quoted in the media recently saying that they should be taxed more. However, it is obviously difficult to raise taxes without risking the attractiveness of Britain as a place to invest in or indeed to live in.
An alternative might be to invite people to increase their own personal tax contribution on a voluntary basis. This could be done on a yearly basis, perhaps alongside the P60. There would need to be a condition that people could also opt out of this tax at a later date.
This petition asks the government to look into the viability of introducing additional voluntary taxation both from a point of view of raising revenue and also the ease of introducing this measure.