At the time of writing, the UK tax system's personal allowance (the amount of money you can earn free of tax) is £7,475. An increase in this rate would be beneficial to entrepreneurs attempting to start a business, because it leaves more money for the entrepreneur to pay other bills, clothe their children, pay the mortgage etc.
The UK government is committed to increasing this allowance to £10,000 by the time its term expires in 2015 (it was one of the things the Lib Dems insisted on).