The criticism from senior Tory party backbenchers follows weeks of dissent from within Conservative Party ranks over the unpopular 50p rate of tax and the launch at the weekend of a new group of Conservative MPs which has been founded to make the case for free enterprise.

Today, the results were published of a survey of over 350 entrepreneurs from 270 of Britain’s growth business taking part in the Entrepreneur Country bi-annual Forum, who issued an impassioned plea to ditch the controversial 50p top rate of tax.

Whilst the Entrepreneur Country survey suggested that SMEs were generally happy with the governments performance on reducing spending and on support for small businesses, an overwhelming 70% of those surveyed urged the Chancellor to ditch the higher rate of tax immediately.

Business builders argued that the 50p rate punishes entrepreneurs who were taking personal risks to drive innovation and growth. Just 6% of the audience believed that it was a fair tax which should be retained, with a further 11% arguing it doesn’t deter entrepreneurs and 13% agreeing with the coalition’s current stance that priorities currently lay elsewhere whilst supporting a future cut.

The capacity audience at the Accelerate Forum in London last week, heard discussion and debate from a dozen of the UK’s most respected entrepreneurs and business leaders. With 5 million small and medium size businesses contributing nearly 14 million jobs, entrepreneurs were clear that the higher rate of tax, which affects 300,000 people in the UK was a disincentive to would-be entrepreneurs who put their livelihoods on the line to start new businesses and create employment and wealth.

The Entrepreneur Country survey comes just a month after twenty high-profile economists wrote to the Financial Times urging the government to drop the top 50p tax rate, which they claimed was doing "lasting damage" to the UK economy. The Chancellor has previously asked HM Revenue and Customs to review how much money is raised for the Treasury by the 50p rate, but has ruled out scrapping the tax until further details from this year's self-assessment tax returns are published in January next year. On the evidence of the Entrepreneur Country survey that decision cannot come soon enough.