The number of self-employed people is set to outstrip the numbers working in the public sector over the next four years, according to new research.

The RSA think tank has estimated that the total number of self-employed in the UK will rise from its current total of 4.4 million to 5 million by 2018.

At the same time, the number of public sector workers is projected to fall from 5.7 million to 4.9 million as government austerity measures continue shrink the state sector.

With the numbers of "micro-businesses" - defined as firms with nine or fewer employees - also on the rise, the RSA said politicians will increasingly have to take account of the small business vote.

Since 2008, the RSA said that the number of microbusinesses had risen by 620,000 - a 13% increase - and now accounted for 95% of all private sector businesses and 32% of private sector employment.

However a Populus poll of 1,006 microbusinesses, commissioned by the RSA found 65% thought the Government was not providing sufficient support while 61% thought the welfare system was unfair to the self-employed and small business owners.

There was strong support for a "significant" cap on immigration - 63% - but views were divided on Britain's membership of the EU with 37% saying they would vote to leave in a referendum as against 40% who would vote to stay.

The Conservatives were judged to have the best policies for small business by 46%, with 10% for Labour, 7% for Ukip and 5% for the Lib Dems.

RSA senior researcher Benedict Dellot, said: "Microbusinesses are the new political force to be reckoned with, but the Government has yet to win their favour.

"Business support remains confusing and superficial, and we have an archaic welfare system that does little to recognise or reward those who want to work for themselves."

A Department for Business, Innovation & Skills spokesman said: "There is a record number of small businesses in the UK, making a vital contribution to the economy contributing almost half of the jobs and a third of the private sector turnover.

"The Government is committed to making the UK the best place to start and grow a business, and is providing targeted support to businesses at all stages to ensure they succeed.

The successful Start Up Loans scheme provides seed capital to help get business ideas off the ground, while advice and support can be sought from experienced business owners through the Mentorsme programme. For those small businesses that want to grow, the Government has set out how it is making it easier for them to get on through Small Business: GREAT Ambition - our commitment to ambitious small firms."

:: Populus carried out its poll between February 24 and March 12.