Let all all UK citizens trade (trade on ebay, run market stalls, do odd jobs etc) on their own account with a turnover of up (say) £12,000 with no strings/taxation/paperwork/red-tape etc.
This could be simply implemented by asking high street banks to setup a new type of account - to be linked to an individuals National Insurance number - the citizen/trader would put all 'business' transactions through their account, and in return the money withdrawn (up to a predetermined limit) would not be subject to tax or 'means testing' against any benefit.
This would legitimise a large part of the 'black economy' and 'benefit cheating' but also remove a huge barrier that many must feel when considering starting a small business. By enabling anyone to try their hand at running their own business so simply, to top up their income with the possibility of developing in to a full business (with VAT, tax, employees etc) - the UK could become a nation of entrepreneurs.
There would be savings to the state in the reduction of investigation and enforcement of low value tax dodging and benefit cheating, and the removal of barriers to 'help oneself' could invigorate an entire class of society to get back to work - generating tax raising opportunities as they succeed/grow, and developing a culture of work and industry to replace any culture of state dependence.
Currently there is little opportunity for poor people in the UK to 'help themselves'. Over the years every avenue of self-help, self-development, self-enterprise has been nationalised or outlawed. This nationalisation has brought overheads, red tape and bureaucracy to such a level that a whole raft of experts are needed to even understand the rules, let alone complying with them - to the extent that the government imposed costs are greater than the likely return of many small enterprises!
So here is a cheap, simple, quick proposal to cut through/sidestep the dross of the past and let people start to help themselves. A proposal that could be implemented in weeks and help millions boost their own incomes and set the UK on the road to be the land of entrepreneurs.
Many poor people (whether poorly paid or on benefits) are already enhancing their incomes by doing small amounts of business in 'the black market' - whether its trading on ebay, doing jobs 'cash in hand', running a market stall etc. I say it is wrong for these peoples enterprise to be crushed by the tax man.
So I suggest the government immediately create a new type of bank account - a Personal Trading Account - every citizen would be entitled to open one such account. Any money paid into and withdrawn from the account (upto maybe £12,000 a year) would be subject to no tax whatsoever.
Stop worrying so much about the 50p tax rate for top earners, first free the bottom earners to make this country great again.